1
|
Liu Y, Feng Y, Dai Y, Huang B, Ma Y. Engineering Layertronics in Two-Dimensional Ferromagnetic Multiferroic Lattice. Nano Lett 2024; 24:3507-3514. [PMID: 38445582 DOI: 10.1021/acs.nanolett.4c00436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
Layertronics, rooted in the layer Hall effect (LHE), is an emerging fundamental phenomenon in condensed matter physics and spintronics. So far, several theoretical and experimental proposals have been made to realize LHE, but all are based on antiferromagnetic systems. Here, using symmetry and tight-binding model analysis, we propose a general mechanism for engineering layertronics in a two-dimensional ferromagnetic multiferroic lattice. The physics is related to the band geometric properties and multiferroicity, which results in the coupling between Berry curvature and layer degree of freedom, thereby generating the LHE. Using first-principles calculations, we further demonstrate this mechanism in bilayer (BL) TcIrGe2S6. Due to the intrinsic inversion and time-reversal symmetry breakings, BL TcIrGe2S6 exhibits multiferroicity with large Berry curvatures at both the center and corners of the Brillouin zone. These Berry curvatures couple with the layer physics, forming the LHE in BL TcIrGe2S6. Our work opens a new direction for research on layertronics.
Collapse
Affiliation(s)
- Yibo Liu
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Str. 27, Jinan 250100, People's Republic of China
| | - Yangyang Feng
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Str. 27, Jinan 250100, People's Republic of China
| | - Ying Dai
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Str. 27, Jinan 250100, People's Republic of China
| | - Baibiao Huang
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Str. 27, Jinan 250100, People's Republic of China
| | - Yandong Ma
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Str. 27, Jinan 250100, People's Republic of China
| |
Collapse
|
2
|
Raj RK, Bindal N, Kaushik BK. Skyrmion motion under temperature gradient and application in logic devices. Nanotechnology 2023; 35:075703. [PMID: 38014695 DOI: 10.1088/1361-6528/acfd33] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Accepted: 09/25/2023] [Indexed: 11/29/2023]
Abstract
Under the presence of temperature gradient (TG) on a nanotrack, it is necessary to investigate the skyrmion dynamics in various magnetic systems under the combined effect of forces due to magnonic spin transfer torque(μSTT),thermal STT (τSTT), entropic difference(dS),as well as thermal induced dipolar field (DF). Hence, in this work, the dynamics of skyrmions in ferromagnets (FM), synthetic antiferromagnets (SAF), and antiferromagnets (AFM) have been studied under different TGs and damping constants (αG). It is observed thatαGplays a major role in deciding the direction of skyrmion motion either towards the hotter or colder side in different magnetic structures. Later, FM skyrmion based logic device is proposed that consists of a cross-coupled nanotrack, where the skyrmions on horizontal and vertical nanotrack are controlled by exploiting TG and electrical STT (eSTT), respectively by taking the advantages of thermal induced skyrmion Hall effect (SkHE). The proposed device performs AND and OR logic functionalities simultaneously, when the applied current density is2×1011Am-2.Moreover, the proposed device is also able to exhibit the half adder functionality by tuning the applied current density to3×1011Am-2.The total energy consumption for AND and OR logic operation and half adder are 33.63 fJ and 25.06 fJ, respectively. This paves the way for the development of energy-efficient logic devices with ultra-high storage density.
Collapse
Affiliation(s)
- Ravish Kumar Raj
- Department of Electronics and Communication Engineering, Indian Institute of Technology, Roorkee 247667, India
| | - Namita Bindal
- Department of Electronics and Communication Engineering, Indian Institute of Technology, Roorkee 247667, India
| | - Brajesh Kumar Kaushik
- Department of Electronics and Communication Engineering, Indian Institute of Technology, Roorkee 247667, India
| |
Collapse
|
3
|
Lukish JT, Williams K, Shah A, Mon R, Lukish JR. The Novel Use of Rare Earth Magnets for the Extraction of Metallic Soft Tissue Foreign Bodies in Children. Surg Innov 2023; 30:571-575. [PMID: 36916247 DOI: 10.1177/15533506231158209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/15/2023]
Abstract
INTRODUCTION Metallic foreign bodies (mFB) are common following penetrating injuries in children. The mFB commonly occur in the head and neck region and extremity soft tissues. Removal may be indicated due to morbidity related to pain or migration. Extraction can be challenging to localize, often requiring wide exposure, and may be difficult to achieve in cosmetically sensitive areas. Different technological adjuncts have been used to facilitate foreign body removal including fluoroscopy, ultrasound, and more recently in adults, surgical magnets. The most powerful commercially available magnets are rare earth magnets comprised of neodymium iron and boron (Ndy). With the goal of reducing radiation exposure and the morbidity of mFB removal with associated soft tissue injury in children, a strategy was introduced utilizing Ndy to optimize extraction with minimal soft tissue surgical dissection. MATERIALS AND METHODS Two children with extremity mFB treated with Ndy between January 2021 and July 2021 were analyzed. We utilized commercially available ring type neodymium-iron-boron magnets with dimensions of 1 3/8-inch outer diameter x 1/8-inch inner diameter and 1/16 inch thick with a power of 13 200 gauss that were processed for use according to our hospital protocols. Our main clinical indication was for the detection and retrieval of small ferromagnetic foreign bodies embedded in superficial extremity soft tissues. RESULTS In the operating room under general anesthesia, the mFB were localized utilizing fluoroscopy. A 1.0 cm skin incision was made into the subdermal soft tissues overlying the area of the mFB. No surgical tissue dissection was performed. The mFB could not be visualized in the soft tissue. Using fluoroscopy to localize the mFB, the Ndy was then placed into the wound in close proximity to the mFB. The mFB were immediately magnetized to the Ndy and the mFB were extracted from the soft tissues without any further surgical dissection. Two simple interrupted nylon sutures were placed to close the incision. The total operative time was 2 and 2.5 minutes respectively. The children recovered uneventfully and are without complication. CONCLUSIONS The use of Ndy to remove extremity soft tissue mFB in children appears to be feasible, safe, and efficient. Use of the Ndy allowed extraction via a small incision, optimizing the aesthetic result and avoiding the need for cross-sectional imaging, extensive surgical dissection, tissue reconstruction and prolonged operative time or x-ray exposure. The development of magnets of increasing energy density may be indicated to further optimize metallic soft tissue foreign body extraction in children in a minimally invasive manner.
Collapse
Affiliation(s)
- John T Lukish
- Kansas City University of Medicine and Biosciences, Kansas City, MO, USA
| | - Kibileri Williams
- Division of Pediatric Surgery, Children's National Hospital, Washington DC, USA
| | - Adil Shah
- Division of Pediatric Surgery, Children's National Hospital, Washington DC, USA
| | - Rodrigo Mon
- Division of Pediatric Surgery, Children's National Hospital, Washington DC, USA
| | - Jeffrey R Lukish
- Division of Pediatric Surgery, Children's National Hospital, Washington DC, USA
- Sheik Zayed Institute for Pediatric Surgical Innovation, Washington DC, USA
- Uniformed Services University of the Health Sciences, Bethesda, MD, USA
- The George Washington University, Washington, DC, USA
| |
Collapse
|
4
|
Liu G, Jiang H, Guo Z, Zhang X, Jin L, Liu C, Liu Y. Magnetic Second-Order Topological Insulators in 2H-Transition Metal Dichalcogenides. Adv Sci (Weinh) 2023; 10:e2301952. [PMID: 37518836 PMCID: PMC10520633 DOI: 10.1002/advs.202301952] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 06/24/2023] [Indexed: 08/01/2023]
Abstract
The transition metal dichalcogenides, 2H-VX2 (X = S, Se, Te), are identified as two-dimensional second-order topological insulator (SOTI) with a ferromagnetic ground state by first-principles calculations. The 2H-VX2 (X = S, Se, Te) materials have a nontrivial band gap in two spin channels is found and exhibit topologically protected corner states with spin-polarization. These corner states only accommodate the quantized fractional charge (e/3). And the charge is bound at the corners of the nanodisk geometry 2H-VX2 (X = S, Se, Te) in real space. The corner states are robust against symmetry-breaking perturbations, which makes them more easily detectable in experiments. Further, it is demonstrated that the SOTI properties of 2H-VX2 (X = S, Se, Te) materials can be maintained in the presence of spin-orbit coupling and are stable against magnetization. Overall, the results reveal 2H-VX2 (X = S, Se, Te) as an ideal platform for the exploration of magnetic SOTI and suggest its great potential in experimental detection.
Collapse
Affiliation(s)
- Guodong Liu
- State Key Laboratory of Reliability and Intelligence of Electrical EquipmentHebei University of TechnologyTianjin300130China
- School of Materials Science and EngineeringHebei University of TechnologyTianjin300130China
| | - Haoqian Jiang
- State Key Laboratory of Reliability and Intelligence of Electrical EquipmentHebei University of TechnologyTianjin300130China
- School of Materials Science and EngineeringHebei University of TechnologyTianjin300130China
| | - Zhenzhou Guo
- State Key Laboratory of Reliability and Intelligence of Electrical EquipmentHebei University of TechnologyTianjin300130China
- School of Materials Science and EngineeringHebei University of TechnologyTianjin300130China
| | - Xiaoming Zhang
- State Key Laboratory of Reliability and Intelligence of Electrical EquipmentHebei University of TechnologyTianjin300130China
- School of Materials Science and EngineeringHebei University of TechnologyTianjin300130China
| | - Lei Jin
- State Key Laboratory of Reliability and Intelligence of Electrical EquipmentHebei University of TechnologyTianjin300130China
- School of Materials Science and EngineeringHebei University of TechnologyTianjin300130China
| | - Cong Liu
- State Key Laboratory of Reliability and Intelligence of Electrical EquipmentHebei University of TechnologyTianjin300130China
- School of Materials Science and EngineeringHebei University of TechnologyTianjin300130China
| | - Ying Liu
- State Key Laboratory of Reliability and Intelligence of Electrical EquipmentHebei University of TechnologyTianjin300130China
- School of Materials Science and EngineeringHebei University of TechnologyTianjin300130China
| |
Collapse
|
5
|
Kumar S, Ahmed F, Shaalan NM, Arshi N, Dalela S, Chae KH. Influence of Fe Doping on the Electrochemical Performance of a ZnO-Nanostructure-Based Electrode for Supercapacitors. Nanomaterials (Basel) 2023; 13:2222. [PMID: 37570540 PMCID: PMC10421403 DOI: 10.3390/nano13152222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 07/25/2023] [Accepted: 07/27/2023] [Indexed: 08/13/2023]
Abstract
ZnO is a potential candidate for providing an economic and environmentally friendly substitute for energy storage materials. Therefore, in this work, Fe-doped ZnO nanostructures prepared using the microwave irradiation procedure were investigated for structural, morphological, magnetic, electronic structural, specific surface area and electrochemical properties to be used as electrodes for supercapacitors. The X-ray diffraction, high-resolution transmission electron microscopy images, and selective-area electron diffraction pattern indicated that the nanocrystalline structures of Fe-doped ZnO were found to possess a hexagonal wurtzite structure. The effect of Fe doping in the ZnO matrix was observed on the lattice parameters, which were found to increase with the dopant concentration. Rods and a nanosheet-like morphology were observed via FESEM images. The ferromagnetic nature of samples is associated with the presence of bound magnetic polarons. The enhancement of saturation magnetization was observed due to Fe doping up to 3% in correspondence with the increase in the number of bound magnetic polarons with an Fe content of up to 3%. This behavior is observed as a result of the change in the oxidation state from +2 to +3, which was a consequence of Fe doping ranging from 3% to 5%. The electrode performance of Fe-doped ZnO nanostructures was studied using electrochemical measurements. The cyclic voltammetry (CV) results inferred that the specific capacitance increased with Fe doping and displayed a high specific capacitance of 286 F·g-1 at 10 mV/s for 3% Fe-doped ZnO nanostructures and decreased beyond that. Furthermore, the stability of the Zn0.97Fe0.03O electrode, which was examined by performing 2000 cycles, showed excellent cyclic stability (85.0% of value retained up to 2000 cycles) with the highest specific capacitance of 276.4 F·g-1, signifying its appropriateness as an electrode for energy storage applications.
Collapse
Affiliation(s)
- Shalendra Kumar
- Department of Physics, College of Science, King Faisal University, P.O. Box 400, Al-Ahsa 31982, Saudi Arabia; (F.A.); (N.M.S.)
- Department of Physics, University of Petroleum & Energy Studies, Dehradun 248007, India
| | - Faheem Ahmed
- Department of Physics, College of Science, King Faisal University, P.O. Box 400, Al-Ahsa 31982, Saudi Arabia; (F.A.); (N.M.S.)
| | - Nagih M. Shaalan
- Department of Physics, College of Science, King Faisal University, P.O. Box 400, Al-Ahsa 31982, Saudi Arabia; (F.A.); (N.M.S.)
- Physics Department, Faculty of Science, Assiut University, Assiut 71516, Egypt
| | - Nishat Arshi
- Department of Basic Sciences, Preparatory Year Deanship, King Faisal University, P.O. Box 400, Al-Ahsa 31982, Saudi Arabia;
| | - Saurabh Dalela
- Department of Pure & Applied Physics, University of Kota, Kota 324005, India;
| | - Keun Hwa Chae
- Advanced Analysis & Data Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea;
| |
Collapse
|
6
|
Esteves DS, Pereira MFC, Ribeiro A, Durães N, Paiva MC, Sequeiros EW. Development of MWCNT/Magnetite Flexible Triboelectric Sensors by Magnetic Patterning. Polymers (Basel) 2023; 15:2870. [PMID: 37447515 DOI: 10.3390/polym15132870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 06/26/2023] [Accepted: 06/27/2023] [Indexed: 07/15/2023] Open
Abstract
The fabrication of low-electrical-percolation-threshold polymer composites aims to reduce the weight fraction of the conductive nanomaterial necessary to achieve a given level of electrical resistivity of the composite. The present work aimed at preparing composites based on multiwalled carbon nanotubes (MWCNTs) and magnetite particles in a polyurethane (PU) matrix to study the effect on the electrical resistance of electrodes produced under magnetic fields. Composites with 1 wt.% of MWCNT, 1 wt.% of magnetite and combinations of both were prepared and analysed. The hybrid composites combined MWCNTs and magnetite at the weight ratios of 1:1; 1:1/6; 1:1/12; and 1:1/24. The results showed that MWCNTs were responsible for the electrical conductivity of the composites since the composites with 1 wt.% magnetite were non-conductive. Combining magnetite particles with MWCNTs reduces the electrical resistance of the composite. SQUID analysis showed that MWCNTs simultaneously exhibit ferromagnetism and diamagnetism, ferromagnetism being dominant at lower magnetic fields and diamagnetism being dominant at higher fields. Conversely, magnetite particles present a ferromagnetic response much stronger than MWCNTs. Finally, optical microscopy (OM) and X-ray micro computed tomography (micro CT) identified the interaction between particles and their location inside the composite. In conclusion, the combination of magnetite and MWCNTs in a polymer composite allows for the control of the location of these particles using an external magnetic field, decreasing the electrical resistance of the electrodes produced. By adding 1 wt.% of magnetite to 1 wt.% of MWCNT (1:1), the electric resistance of the composites decreased from 9 × 104 to 5 × 103 Ω. This approach significantly improved the reproducibility of the electrode's fabrication process, enabling the development of a triboelectric sensor using a polyurethane (PU) composite and silicone rubber (SR). Finally, the method's bearing was demonstrated by developing an automated robotic soft grip with tendon-driven actuation controlled by the triboelectric sensor. The results indicate that magnetic patterning is a versatile and low-cost approach to manufacturing sensors for soft robotics.
Collapse
Affiliation(s)
- David Seixas Esteves
- Department of Metallurgical and Materials Engineering, Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal
- CENTI, Centre for Nanotechnology and Smart Materials, 4760-034 Vila Nova de Famalicão, Portugal
| | - Manuel F C Pereira
- CERENA, Center for Natural Resources and Environment, IST, University of Lisbon, 1049-001 Lisboa, Portugal
| | - Ana Ribeiro
- CENTI, Centre for Nanotechnology and Smart Materials, 4760-034 Vila Nova de Famalicão, Portugal
| | - Nelson Durães
- CENTI, Centre for Nanotechnology and Smart Materials, 4760-034 Vila Nova de Famalicão, Portugal
| | - Maria C Paiva
- Department of Polymer Engineering, Institute for Polymers and Composites, University of Minho, 4800-058 Guimarães, Portugal
| | - Elsa W Sequeiros
- Department of Metallurgical and Materials Engineering, Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal
- INEGI-Institute of Science and Innovation in Mechanical and Industrial Engineering, 4200-465 Porto, Portugal
| |
Collapse
|
7
|
Neilo A, Bakurskiy S, Klenov N, Soloviev I, Kupriyanov M. Tunnel Josephson Junction with Spin-Orbit/ Ferromagnetic Valve. Nanomaterials (Basel) 2023; 13:1970. [PMID: 37446484 DOI: 10.3390/nano13131970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 06/26/2023] [Accepted: 06/27/2023] [Indexed: 07/15/2023]
Abstract
We have theoretically studied the transport properties of the SIsNSOF structure consisting of thick (S) and thin (s) films of superconductor, an insulator layer (I), a thin film of normal metal with spin-orbit interaction (SOI) (NSO), and a monodomain ferromagnetic layer (F). The interplay between superconductivity, ferromagnetism, and spin-orbit interaction allows the critical current of this Josephson junction to be smoothly varied over a wide range by rotating the magnetization direction in the single F-layer. We have studied the amplitude of the spin valve effect and found the optimal ranges of parameters.
Collapse
Affiliation(s)
- Alexey Neilo
- National University of Science and Technology MISIS, 119049 Moscow, Russia
- Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Sergey Bakurskiy
- National University of Science and Technology MISIS, 119049 Moscow, Russia
- Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Nikolay Klenov
- National University of Science and Technology MISIS, 119049 Moscow, Russia
- Faculty of Physics, Moscow State University, 119991 Moscow, Russia
| | - Igor Soloviev
- National University of Science and Technology MISIS, 119049 Moscow, Russia
- Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Mikhail Kupriyanov
- National University of Science and Technology MISIS, 119049 Moscow, Russia
- Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119991 Moscow, Russia
| |
Collapse
|
8
|
Ali MA, Bahajjaj AAA, Al-Qaisi S, Sillanpää M, Khan A, Wang X. Structural, electronic, magnetic and thermoelectric properties of Tl 2 NbX 6 (X = Cl, Br) variant perovskites calculated via density functional theory. J Comput Chem 2023. [PMID: 37224190 DOI: 10.1002/jcc.27166] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 04/07/2023] [Accepted: 05/11/2023] [Indexed: 05/26/2023]
Abstract
This article presents detailed structural, electronic, magnetic, and thermoelectric properties of two experimentally existing isostructural variant perovskite compounds Tl2 NbX6 (X = Cl, Br) with the help of first principles calculations. As per requirement of stability in the device applications, the structural and thermodynamic stabilities were, respectively verified by tolerance factor and negative formation energies. The structural parameters in ferromagnetic phase were calculated and found in close agreement with the available experimental results. The electronic nature was found as half metallic from spin polarized calculations of electronic band structures and density of states, where the semiconductor nature was found in the spin down states and metallic nature in the spin up states. The magnetic moments of both the compounds were calculated as 1 μB majorly contributed by Nb atom. The Boltzmann transport theory was implemented via BoltzTraP for calculating the spin resolved thermoelectric parameters, such as Seebeck coefficient, electronic and thermal conductivities, and figure of merit. Overall, both the compounds were found suitable for use in spintronics and spin Seebeck effect for energy applications.
Collapse
Affiliation(s)
- Malak Azmat Ali
- Department of Physics, Government Post Graduate Jahanzeb College Saidu Sharif, Swat, Pakistan
| | | | - Samah Al-Qaisi
- Palestinian Ministry of Education and Higher Education, Nablus, Palestine
| | - Mika Sillanpää
- Department of Biological and Chemical Engineering, Aarhus University, Aarhus, Denmark
| | - Afzal Khan
- Department of Physics, University of Peshawar, Peshawar, Pakistan
| | - Xiaoyu Wang
- State Key Labortory of Superhard Materials, Key Labortory of Automobile Mateials of MOE, Jilin Provential Intenational Cooperation Key Labortory of High-Efficiency Clean Energy Materials, School of Materials Science and Engineering, Jilin University, Changchun, China
| |
Collapse
|
9
|
Yang F, Hu P, Yang FF, Chen B, Yin F, Sun R, Hao K, Zhu F, Wang K, Yin Z. Emerging Enhancement and Regulation Strategies for Ferromagnetic 2D Transition Metal Dichalcogenides. Adv Sci (Weinh) 2023:e2300952. [PMID: 37178366 PMCID: PMC10375142 DOI: 10.1002/advs.202300952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 04/18/2023] [Indexed: 05/15/2023]
Abstract
Two-dimensional transition metal dichalcogenides (2D TMDs) present promising applications in various fields such as electronics, optoelectronics, memory devices, batteries, superconductors, and hydrogen evolution reactions due to their regulable energy band structures and unique properties. For emerging spintronics applications, materials with excellent room-temperature ferromagnetism are required. Although most transition metal compounds do not possess room-temperature ferromagnetism on their own, they are widely modified by researchers using the emerging strategies to engineer or modulate their intrinsic properties. This paper reviews recent enhancement approaches to induce magnetism in 2D TMDs, mainly using doping, vacancy defects, composite of heterostructures, phase modulation, and adsorption, and also by electron irradiation induction, O plasma treatment, etc. On this basis, the produced effects of these methods for the introduction of magnetism into 2D TMDs are compressively summarized and constructively discussed. For perspective, research on magnetic doping techniques for 2D TMDs materials should be directed toward more reliable and efficient directions, such as exploring advanced design strategies to combine dilute magnetic semiconductors, antiferromagnetic semiconductors, and superconductors to develop new types of heterojunctions; and advancing experimentation strategies to fabricate the designed materials and enable their functionalities with simultaneously pursuing the upscalable growth methods for high-quality monolayers to multilayers.
Collapse
Affiliation(s)
- Fan Yang
- School of Metallurgy Engineering, State Local Joint Engineering Research Center for Functional Materials Processing, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Ping Hu
- School of Metallurgy Engineering, State Local Joint Engineering Research Center for Functional Materials Processing, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Fairy Fan Yang
- School of Metallurgy Engineering, State Local Joint Engineering Research Center for Functional Materials Processing, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Bo Chen
- School of Metallurgy Engineering, State Local Joint Engineering Research Center for Functional Materials Processing, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Fei Yin
- School of Metallurgy Engineering, State Local Joint Engineering Research Center for Functional Materials Processing, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Ruiyan Sun
- School of Metallurgy Engineering, State Local Joint Engineering Research Center for Functional Materials Processing, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Ke Hao
- School of Metallurgy Engineering, State Local Joint Engineering Research Center for Functional Materials Processing, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Fei Zhu
- School of Metallurgy Engineering, State Local Joint Engineering Research Center for Functional Materials Processing, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Kuaishe Wang
- School of Metallurgy Engineering, State Local Joint Engineering Research Center for Functional Materials Processing, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Zongyou Yin
- Research School of Chemistry, The Australian National University, Canberra, ACT 2601, Australia
| |
Collapse
|
10
|
Li H, Niu D, Zhang Z, Yang F, Wang H, Cheng W. One-Dimensional Mn 5Si 3 Nanorods: Fabrication, Microstructure, and Magnetic Properties via a Novel Casting-Extraction Route. Materials (Basel) 2023; 16:ma16093540. [PMID: 37176422 PMCID: PMC10179953 DOI: 10.3390/ma16093540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 04/29/2023] [Accepted: 05/02/2023] [Indexed: 05/15/2023]
Abstract
This study presents a simple and innovative approach for producing one-dimensional Mn5Si3 nanorods through a casting-extraction process. In this technique, the Mn5Si3 nanorods were synthesized by reacting Mn and Si during brass solidification and extracted by electrochemical etching of the brass matrix. The effect of the cooling rate during casting on the nanorods' dimension, morphology, and magnetic properties was investigated. The results demonstrate that the prepared high-purity Mn5Si3 nanorods had a single-crystal D88 structure and exhibited ferromagnetism at room temperature. The morphology of the nanorods was an elongated hexagonal prism, and their preferred growth was along the [0001] crystal direction. Increasing the cooling rate from 5 K/s to 50 K/s lead to a decrease in the dimension of the nanorods but an increase in their ferromagnetism. At the optimal cooling rate of 50 K/s, the nanorods had a diameter and length range of approximately 560 nm and 2~11 μm, respectively, with a highest saturation magnetization of 7.5 emu/g, and a maximum coercivity of 120 Oe. These properties make the fabricated Mn5Si3 nanorods potentially useful for magnetic storage applications, and this study also provides a new perspective on the preparation of one-dimensional nanomaterials.
Collapse
Affiliation(s)
- Hang Li
- School of Material Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China
- Golden Dragon Precise Copper Tube Group Inc., Chongqing 404100, China
| | - Dongtao Niu
- School of Material Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Zhongtao Zhang
- Golden Dragon Precise Copper Tube Group Inc., Chongqing 404100, China
| | - Fan Yang
- School of Material Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Hongxia Wang
- School of Material Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Weili Cheng
- School of Material Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| |
Collapse
|
11
|
Li C, Li M, Li Y, He T, Liu Y, Zhang X, Dai X, Liu G. Two-dimensional half-metallicity and fully spin-polarized topological fermions in monolayer EuOBr. J Phys Condens Matter 2023; 35:264002. [PMID: 36990099 DOI: 10.1088/1361-648x/acc8b2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 03/29/2023] [Indexed: 06/19/2023]
Abstract
Two-dimensional (2D) half-metal and topological states have been the current research focus in condensed matter physics. Herein, we report a novel 2D material named EuOBr monolayer, which can simultaneously show 2D half-metal and topological fermions. This material shows a metallic state in the spin-up channel but a large insulating gap of 4.38 eV in the spin-down channel. In the conducting spin channel, the EuOBr monolayer shows the coexistence of Weyl points and nodal-lines near the Fermi level. These nodal-lines are classified by type-I, hybrid, closed, and open nodal-lines. The symmetry analysis suggests these nodal-lines are protected by the mirror symmetry, which cannot be broken even spin-orbit coupling is included because the ground magnetization direction in the material is out-of-plane [001]. The topological fermions in the EuOBr monolayer are fully spin-polarized, which can be meaningful for future applications in topological spintronic nano-devices.
Collapse
Affiliation(s)
- Chenyao Li
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300130, People's Republic of China
- School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130, People's Republic of China
| | - Minghang Li
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300130, People's Republic of China
- School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130, People's Republic of China
| | - Yefeng Li
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300130, People's Republic of China
- School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130, People's Republic of China
| | - Tingli He
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300130, People's Republic of China
- School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130, People's Republic of China
| | - Ying Liu
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300130, People's Republic of China
- School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130, People's Republic of China
| | - Xiaoming Zhang
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300130, People's Republic of China
- School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130, People's Republic of China
| | - Xuefang Dai
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300130, People's Republic of China
- School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130, People's Republic of China
| | - Guodong Liu
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300130, People's Republic of China
- School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130, People's Republic of China
| |
Collapse
|
12
|
Bhambhani R, Roy SS, Joshi S. Magnetic resonance imaging investigations in patients with metallic dental prosthesis: "The associated dilemma for medical fraternity and the dentist's role". J Indian Prosthodont Soc 2023; 23:203-206. [PMID: 37102548 PMCID: PMC10262089 DOI: 10.4103/jips.jips_473_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 03/12/2023] [Accepted: 03/15/2023] [Indexed: 04/28/2023] Open
Abstract
Background Interdisciplinary referrals for dental examination in hospital setups are common before radiotherapy, kidney transplants, or magnetic resonance imaging (MRI). The patients who walk in could be random patients with metallic or porcelain-fused-to-metal prostheses done elsewhere but might require an opinion before the MRI. This leaves quite a responsibility on the consulting dentist to green signal the procedure. There is a lack of evidence in the literature, to confirm the absence of any untoward consequence during such MRI, which might leave the dentist in dilemma. Dental materials' magnetic behavior raises concern regarding whether they are 100% nonferromagnetic; furthermore, the examining dentist might be unaware of the metal used (Co-Cr, Ni-Cr, or trace elements). Clinicians may also come across full-mouth rehabilitated patients with multiple crown-bridge prostheses or metallic superstructure for implant prostheses. Research in the area leaves many unanswered questions because most studies have evaluated artifacts during MRI and are in vitro. Titanium is considered to be safe due to its paramagnetic behavior, whereas the literature does not rule out the probability of dislodgment of other porcelain fused to metal (PFM) prostheses. Due to less reported literature there exists dilemma to ascertain MRI in these patients. An online Google Search, PubMed, and gray literature portray the ambiguity associated with metal and PFM crowns and their magnetic behavior during MRI. Most studies were associated with the artifacts caused during MRI and methods of reducing them under in vitro situations. The concern for dislodgment has also been expressed in a few reports. Technique Certain steps of a pre-MRI checkup and an innovative technique have been discussed to assure patient safety during the MRI. Conclusion The technique explained is inexpensive and a quick aid that can be executed before the investigation. Clinical and Research Implications There is a need to study and understand the magnetic behavior of Co-Cr and Ni-Cr crowns in the presence of various MRI strengths.
Collapse
Affiliation(s)
- Ritika Bhambhani
- Department of Prosthodontics, Gurunank Institute of Dental Sciences and Research, Kolkata, West Bengal, India
| | - Santanu Sen Roy
- Department of Public Health Dentistry, Gurunank Institute of Dental Sciences and Research, Kolkata, West Bengal, India
| | - Shubha Joshi
- Department of Prosthodontics, Krishna Institute of Medical Sciences, Karad, Maharashtra, India
| |
Collapse
|
13
|
Zhang SJ, Chen L, Li SS, Zhang Y, Yan JM, Tang F, Fang Y, Fei LF, Zhao W, Karel J, Chai Y, Zheng RK. Coexistence of logarithmic and SdH quantum oscillations in ferromagnetic Cr-doped tellurium single crystals. J Phys Condens Matter 2023; 35:245701. [PMID: 36940480 DOI: 10.1088/1361-648x/acc5ca] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 03/20/2023] [Indexed: 06/18/2023]
Abstract
We report the synthesis of transition-metal-doped ferromagnetic elemental single-crystal semiconductors with quantum oscillations using the physical vapor transport method. The 7.7 atom% Cr-doped Te crystals (Cr:Te) show ferromagnetism, butterfly-like negative magnetoresistance in the low temperature (<3.8 K) and low field (<0.15 T) region, and high Hall mobility, e.g. 1320 cm2V-1s-1at 30 K and 350 cm2V-1s-1at 300 K, implying that Cr:Te crystals are ferromagnetic elemental semiconductors. WhenB// [001] // I, the maximum negative MR is ∼-27% atT= 20 K andB= 8 T. In the low temperature semiconducting region, Cr:Te crystals show strong discrete scale invariance dominated logarithmic quantum oscillations when the direction of the magnetic fieldBis parallel to the [100] crystallographic direction (B// [100]) and show Landau quantization dominated Shubnikov-de Haas oscillations forB// [210] direction, which suggests the broken rotation symmetry of the Fermi pockets in the Cr:Te crystals. The findings of coexistence of multiple quantum oscillations and ferromagnetism in such an elemental quantum material may inspire more study of narrow bandgap semiconductors with ferromagnetism and quantum phenomena.
Collapse
Affiliation(s)
- Shu-Juan Zhang
- School of Materials and Mechanic & Electrical Engineering, Jiangxi Science and Technology Normal University, Nanchang 330038, People's Republic of China
| | - Lei Chen
- School of Physics and Materials Science, Guangzhou University, Guangzhou 510006, People's Republic of China
| | - Shuang-Shuang Li
- School of Materials Science and Engineering and Jiangxi Engineering Laboratory for Advanced Functional Thin Films, Nanchang University, Nanchang 330031, People's Republic of China
| | - Ying Zhang
- School of Materials Science and Engineering and Jiangxi Engineering Laboratory for Advanced Functional Thin Films, Nanchang University, Nanchang 330031, People's Republic of China
| | - Jian-Min Yan
- Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong 999077, People's Republic of China
| | - Fang Tang
- Jiangsu Laboratory of Advanced Functional Materials, Department of Physics, Changshu Institute of Technology, Changshu 215500, People's Republic of China
| | - Yong Fang
- Jiangsu Laboratory of Advanced Functional Materials, Department of Physics, Changshu Institute of Technology, Changshu 215500, People's Republic of China
| | - Lin-Feng Fei
- School of Materials Science and Engineering and Jiangxi Engineering Laboratory for Advanced Functional Thin Films, Nanchang University, Nanchang 330031, People's Republic of China
| | - Weiyao Zhao
- Department of Materials Science & Engineering, & ARC Centre of Excellence in Future Low-Energy Electronics Technologies, Monash University, Clayton, VIC 3800, Australia
| | - Julie Karel
- Department of Materials Science & Engineering, & ARC Centre of Excellence in Future Low-Energy Electronics Technologies, Monash University, Clayton, VIC 3800, Australia
| | - Yang Chai
- Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong 999077, People's Republic of China
| | - Ren-Kui Zheng
- School of Physics and Materials Science, Guangzhou University, Guangzhou 510006, People's Republic of China
| |
Collapse
|
14
|
Abstract
The realization and control of the quantum anomalous Hall (QAH) effect are highly desirable for the development of spintronic and quantum devices. In this work, we propose a van der Waals (vdW) heterostructure of ultrathin MnBi2Se4 and Bi2Se3 layers and demonstrate that it is an excellent tunable QAH platform by using model Hamiltonian and density functional theory simulations. Its band gap closes and reopens as external electric field increases, manifesting a novel topological phase transition with an electric field of ∼0.06 V/Å. This heterostructure has other major advantageous, such as large topological band gap, perpendicular magnetization, and strong ferromagnetic ordering. Our work provides clear physical insights and suggests a new strategy for experimental realization and control of the QAH effect in real materials.
Collapse
Affiliation(s)
- Jie Li
- School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
- Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, United States
| | - Ruqian Wu
- Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, United States
| |
Collapse
|
15
|
Xia W, Li C, Zhang S, Wang X, Wang S, Yang Q, Li W, Xiong C, Huang J, Wang Q. Ho-Ion-Polymer/Graphene Heterojunctions Toward Room-Temperature Ferromagnets. Small 2023:e2300385. [PMID: 36929570 DOI: 10.1002/smll.202300385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 02/21/2023] [Indexed: 06/18/2023]
Abstract
Organic ferromagnetic materials offer great promise for spintronic devices, carbon-based chips, and quantum communications, but remain as a challenging issue due to their low saturation magnetization and/or unsustainable ferromagnetic properties. To date, magnetic ion polymers have displayed paramagnetism without exception at room-temperature. In this study, it is reported for the first time that, owing to the structural restriction and charge exchange of Ho ion by polymer/graphene π-π stacking heterojunctions, holmium ion polymer composites exhibited typical hysteresis lines of ferromagnetic materials at room temperature. The room-temperature ferromagnetic ion polymer composite presented the highest saturation magnetization value of 3.36 emu g-1 and unprecedented sustainable ferromagnetism, compared to reported room-temperature organic ferromagnetic materials. Accordingly, prepared ferromagnetic composites also achieved impressive wave absorption properties, with a maximum reflection loss of as much as -57.32 dB and a broad absorption bandwidth of 5.05 GHz. These findings may promote the development of room-temperature organic ferromagnetic materials.
Collapse
Affiliation(s)
- Wenlai Xia
- State Key Laboratory of Silicate Materials for Architectures, School of Materials Science and Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, 430070, P. R. China
| | - Chenjian Li
- State Key Laboratory of Silicate Materials for Architectures, School of Materials Science and Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, 430070, P. R. China
| | - Shixian Zhang
- State Key Laboratory of Silicate Materials for Architectures, School of Materials Science and Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, 430070, P. R. China
| | - Xuelin Wang
- State Key Laboratory of Silicate Materials for Architectures, School of Materials Science and Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, 430070, P. R. China
| | - Shan Wang
- State Key Laboratory of Silicate Materials for Architectures, School of Materials Science and Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, 430070, P. R. China
| | - Quanling Yang
- State Key Laboratory of Silicate Materials for Architectures, School of Materials Science and Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, 430070, P. R. China
| | - Wei Li
- State Key Laboratory of Silicate Materials for Architectures, School of Materials Science and Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, 430070, P. R. China
| | - Chuanxi Xiong
- State Key Laboratory of Silicate Materials for Architectures, School of Materials Science and Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, 430070, P. R. China
| | - Jing Huang
- State Key Laboratory for New Textile Materials & Advanced Processing Technology, School of Materials Science and Engineering, Wuhan Textile University, Sunshine Avenue 1, Wuhan, 430200, P. R. China
| | - Qing Wang
- State Key Laboratory of Silicate Materials for Architectures, School of Materials Science and Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, 430070, P. R. China
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| |
Collapse
|
16
|
Liu Y, Chen X, Liang Y, Song H, Yu P, Guan S, Liu Z, Yang A, Tang M, Zhou Y, Zheng Y, Yang Z, Jiang L, He J, Tan N, Xu B, Lin X. Ferromagnetic Flexible Electronics for Brain-Wide Selective Neural Recording. Adv Mater 2023; 35:e2208251. [PMID: 36451587 DOI: 10.1002/adma.202208251] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 11/09/2022] [Indexed: 06/17/2023]
Abstract
Flexible microelectronics capable of straightforward implantation, remotely controlled navigation, and stable long-term recording hold great promise in diverse medical applications, particularly in deciphering complex functions of neural circuits in the brain. Existing flexible electronics, however, are often limited in bending and buckling during implantation, and unable to access a large brain region. Here, an injectable class of electronics with stable recording, omnidirectional steering, and precise navigating capabilities based on magnetic actuation is presented. After simple transcriptional injection, the rigid coatings are biodegraded quickly and the bundles of magnetic-nanoparticles-coated microelectrodes become separated, ultra-flexible, and magnetic actuated for further minimally invasive three-dimensional interpenetration in the brain. As proof of concept, this paradigm-shifting approach is demonstrated for selective and multiplexed neural activities recording across distant regions in the deep rodent brains. Coupling with optogenetic neural stimulation, the unique capabilities of this platform in electrophysiological readouts of projection dynamics in vivo are also demonstrated. The ability of these miniaturized, remotely controllable, and biocompatible ferromagnetic flexible electronics to afford minimally invasive manipulations in the soft tissues of the mammalian brain foreshadows applications in other organ systems, with great potential for broad utility in biomedical science and engineering.
Collapse
Affiliation(s)
- Yuxin Liu
- Guangdong Provincial Key Laboratory of Sensor Technology and Biomedical Instrument, School of Biomedical Engineering, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, Guangdong, 518107, China
| | - Xi Chen
- Department of Neuroscience, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, 999077, China
| | - Ye Liang
- Department of Neuroscience, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, 999077, China
| | - Hao Song
- Guangdong Provincial Key Laboratory of Sensor Technology and Biomedical Instrument, School of Biomedical Engineering, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, Guangdong, 518107, China
| | - Peng Yu
- School of Computer Science and Engineering, Key Laboratory of Machine Intelligence and Advanced Computing, Ministry of Education, Sun Yat-sen University, Guangzhou, Guangdong, 510275, China
| | - Shunmin Guan
- Guangdong Provincial Key Laboratory of Sensor Technology and Biomedical Instrument, School of Biomedical Engineering, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, Guangdong, 518107, China
| | - Zijian Liu
- Guangdong Provincial Key Laboratory of Sensor Technology and Biomedical Instrument, School of Biomedical Engineering, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, Guangdong, 518107, China
| | - Anqi Yang
- Guangdong Provincial Key Laboratory of Sensor Technology and Biomedical Instrument, School of Biomedical Engineering, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, Guangdong, 518107, China
| | - Minghui Tang
- Guangdong Provincial Key Laboratory of Sensor Technology and Biomedical Instrument, School of Biomedical Engineering, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, Guangdong, 518107, China
| | - Yajing Zhou
- Guangdong Provincial Key Laboratory of Sensor Technology and Biomedical Instrument, School of Biomedical Engineering, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, Guangdong, 518107, China
| | - Ying Zheng
- Guangdong Provincial Key Laboratory of Sensor Technology and Biomedical Instrument, School of Biomedical Engineering, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, Guangdong, 518107, China
| | - Zhilun Yang
- Guangdong Provincial Key Laboratory of Sensor Technology and Biomedical Instrument, School of Biomedical Engineering, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, Guangdong, 518107, China
| | - Lelun Jiang
- Guangdong Provincial Key Laboratory of Sensor Technology and Biomedical Instrument, School of Biomedical Engineering, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, Guangdong, 518107, China
| | - Jufang He
- Department of Neuroscience, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, 999077, China
| | - Ning Tan
- School of Computer Science and Engineering, Key Laboratory of Machine Intelligence and Advanced Computing, Ministry of Education, Sun Yat-sen University, Guangzhou, Guangdong, 510275, China
| | - Bingzhe Xu
- Guangdong Provincial Key Laboratory of Sensor Technology and Biomedical Instrument, School of Biomedical Engineering, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, Guangdong, 518107, China
| | - Xudong Lin
- Guangdong Provincial Key Laboratory of Sensor Technology and Biomedical Instrument, School of Biomedical Engineering, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, Guangdong, 518107, China
| |
Collapse
|
17
|
Song M, Yang SC. Investigation of Ferromagnetic and Ferroelectric Properties in Binderless Cellulose/Ni Laminates for Magnetoelectric Applications. Polymers (Basel) 2022; 14:polym14245347. [PMID: 36559712 PMCID: PMC9784961 DOI: 10.3390/polym14245347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 12/02/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022] Open
Abstract
According to reported polymer-based magnetoelectric (ME) laminates, which generate voltage via an external magnetic field, a binder is indispensable for the adhesion between phases. However, if the binder is excluded, the ME response is expected to improve via efficient strain transfer from the magnetostrictive phase to the piezoelectric phase. Nevertheless, an understanding of the binderless state has not yet been addressed in polymer-based ME laminates. In this study, cellulose/Ni (CN) laminates were designed to obtain binderless polymer-based ME laminates. The surface properties of Ni foil desirable for the anchoring effect and the electrostatic interactions required for binderless states were determined via heat treatment of the Ni substrate. Moreover, to confirm the potential of the binderless laminate in ME applications, the ferromagnetic and ferroelectric properties of the CN laminates were recorded. Consequently, the CN laminates exhibited remnant and saturation magnetizations of 29.5 emu/g and 55.2 emu/g, respectively. Furthermore, the significantly increased remnant and saturation polarization of the CN laminates were determined to be 1.86 µC/cm2 and 0.378 µC/cm2, an increase of approximately 35-fold and 5.56-fold, respectively, compared with a neat cellulose film. The results indicate that multiferroic binderless CN laminates are excellent candidates for high-response ME applications.
Collapse
|
18
|
Xiao A, Zhou Z, Qian Y, Wang X. Direct Observation of Evolution from Amorphous Phase to Strain Glass. Materials (Basel) 2022; 15:ma15227900. [PMID: 36431386 PMCID: PMC9692269 DOI: 10.3390/ma15227900] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Revised: 10/09/2022] [Accepted: 11/07/2022] [Indexed: 06/12/2023]
Abstract
The amorphous phase and strain glass are both disordered states of solids. The amorphous phase is an atomic packing disordered phase, while strain glass is a glassy state with transformation strain disorder in a crystalline matrix, which both bring extraordinary properties to alloys. Previous studies have mostly focused on the properties and structure of single glass; however, the link between them has seldom been considered. In this work, the specimen of the almost amorphous state was obtained from the heavy-defects-doping Fe67.8Pd32.2 strain glass ingot by arc melting and 90% cold rolling, which were characterized by amorphous packages in X-ray diffraction and amorphous rings in transmission electron microscope diffraction. The evolution from the amorphous phase (metallic glass) back to strain glass was directly observed by an in situ high-resolution transmission electron microscope, which revealed that strain nanodomains began to form on the amorphous matrix below the crystallization temperature of the amorphous phase. Here, direct observation of the evolution process provides a theoretical basis for achieving precise control of crystallinity to obtain the desired microstructure, while the study of the unusual crystallization process offers a possible way to tailor the mechanical and functional properties through tuning the amorphous and strain glass coexistence. This work presents the specific pathway and realization possibilities for the design of glass composite materials with enhanced properties.
Collapse
|
19
|
Shi Y, Jia N, Cai J, Lyu Z, Liu Z. 2D electrene LaH 2monolayer: an ideal ferrovalley direct semiconductor with room-temperature ferromagnetic stability. J Phys Condens Matter 2022; 34:475303. [PMID: 36179704 DOI: 10.1088/1361-648x/ac96bb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
In developing nonvolatile valleytronic devices, ferromagnetic (FM) ferrovalley semiconductors are critically needed due to the existence of spontaneous valley polarization. At present, however, the known real materials have various drawbacks towards practical applications, including the in-plane FM ground state, low Curie temperature (TC), small valley polarization, narrow energy window with clean polarized valley, and indirect bandgap. From first-principles calculations, here we predict anideal ferrovalley semiconductor, honeycomb LaH2monolayer (ML), whose intrinsic properties can overcome all these shortcomings. We demonstrate that LaH2ML, having satisfied structural stability, is a FM half-semiconducting electrene (La3+2H-⋅e-) with its magnetic moments localized at the lattice interstitial sites rather than La atoms. At the same time, LaH2ML holds the following desired attributes: a robust out-of-plane FM ground state with a highTC(334 K), a sizable valley polarization (166 meV), a wide energy window (137 meV) harboring clean single-valley carriers, and a direct bandgap. These results identify a much needed ideal ferrovalley semiconductor candidate, holding the promising application potential in valleytronics and spintronics devices.
Collapse
Affiliation(s)
- Yongting Shi
- School of Physical Science and Technology, Inner Mongolia University, Hohhot 010021, People's Republic of China
| | - Ningning Jia
- School of Physical Science and Technology, Inner Mongolia University, Hohhot 010021, People's Republic of China
| | - Jiangtao Cai
- Department of Physics, Shaanxi University of Science and Technology, Xi'an 710021, People's Republic of China
| | - Zhiheng Lyu
- School of Physical Science and Technology, Inner Mongolia University, Hohhot 010021, People's Republic of China
| | - Zhifeng Liu
- School of Physical Science and Technology, Inner Mongolia University, Hohhot 010021, People's Republic of China
| |
Collapse
|
20
|
Lin TC, Qi X. Cation Valences and Multiferroic Properties of EuTiO 3 Co-Doped with Ba and Transition Metals of Co/Ni. Materials (Basel) 2022; 15:6652. [PMID: 36233994 PMCID: PMC9572895 DOI: 10.3390/ma15196652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 09/15/2022] [Accepted: 09/22/2022] [Indexed: 06/16/2023]
Abstract
Eu1-xBaxTi1-yMyO3 (M = Co or Ni) was sintered at 1400 °C under a reduction atmosphere. X-ray photoelectron spectroscopy revealed the mixed valences of Eu2+/Eu3+ and Ti4+/Ti3+ in EuTiO3 and Eu0.7Ba0.3TiO3, as well as some oxygen vacancies required to keep the charge neutrality. The co-doping of Co2+/Ni2+ in Eu0.7Ba0.3TiO3 resulted in the disappearance of oxygen vacancies, as a result of a reduction in Ti3+ numbers and an increase in Eu3+ numbers. On the other hand, Ba2+ doping led to an increased lattice parameter due to its larger ionic size than Eu2+, whereas the Co2+/Ni2+ co-doping resulted in smaller lattice parameters because of the combined effects of ionic size and variation in the oxygen-vacancy numbers. Eu0.7Ba0.3TiO3 exhibited a clear ferroelectricity, which persisted in the Co2+/Ni2+ co-doped samples until the doping levels of y = 0.05 and 0.10, respectively. Eu0.7Ba0.3TiO3 remained to be antiferromagnetic with a reduced transition temperature of 3.1 K, but co-doping of Co2+/Ni2+ turned the samples from antiferromagnetic to ferromagnetic with transition temperatures of 2.98 K and 2.72 K, respectively. The cause for such a transition could not be explained by the larger lattice volume, oxygen vacancies and mixed valences of Eu2+/Eu3+, which were proposed in previous works. Instead, it was more likely to arise from a large asymmetric distortion of the Eu-O polyhedron introduced by the aliovalent doping, which promotes the admixture of Eu 5d and 4f states.
Collapse
Affiliation(s)
- Tzu-Chiao Lin
- Department of Materials Science and Engineering, National Cheng Kung University, Tainan City 70101, Taiwan
| | - Xiaoding Qi
- Department of Materials Science and Engineering, National Cheng Kung University, Tainan City 70101, Taiwan
- Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan City 70101, Taiwan
| |
Collapse
|
21
|
McKeever C, Aziz M. Effect of Multilayered Structure on the Static and Dynamic Properties of Magnetic Nanospheres. ACS Appl Mater Interfaces 2022; 14:35177-35183. [PMID: 35879264 PMCID: PMC9354015 DOI: 10.1021/acsami.2c05715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The development of flexible and lightweight electromagnetic interference (EMI)-shielding materials and microwave absorbers requires precise control and optimization of core-shell constituents within composite materials. Here, a theoretical model is proposed to predict the static and dynamic properties of multilayered core-shell particles comprised of exchange-coupled layers, as in the case of a spherical iron core coupled to an oxide shell across a spacer layer. The theory of exchange resonance in homogeneous spheres is shown to be a limiting special case of this more general theory. Nucleation of magnetization reversal occurs through either quasi-uniform or curling magnetization processes in core-shell particles, where a purely homogeneous magnetization configuration is forbidden by the multilayered morphology. The energy is minimized through mixing of modes for specific interface conditions, leading to many inhomogeneous solutions, which grow as 2n with increasing layers, where n represents the number of magnetic layers. The analytical predictions are confirmed using numerical simulations.
Collapse
Affiliation(s)
- Conor McKeever
- Department
of Physics and Astronomy, University of
Exeter, Exeter EX4 4QL, United Kingdom
- MaxLLG,
Exeter Science Park, Exeter EX5 2FN, United Kingdom
| | - Mustafa Aziz
- Department
of Engineering, University of Exeter, Exeter EX4 4QF, United Kingdom
- MaxLLG,
Exeter Science Park, Exeter EX5 2FN, United Kingdom
| |
Collapse
|
22
|
Szklarzewicz J, Hodorowicz M, Jurowska A, Baran S. The High-Temperature Soft Ferromagnetic Molecular Materials Based on [W(CN) 6(bpy)] 2-/- System. Molecules 2022; 27:molecules27144525. [PMID: 35889398 PMCID: PMC9315671 DOI: 10.3390/molecules27144525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 07/04/2022] [Accepted: 07/12/2022] [Indexed: 11/16/2022]
Abstract
The synthesis of molecular materials with magnetic properties, in particular ferromagnetic properties, has been the subject of interest in coordination chemistry for decades. In the last three decades, research has accelerated, as it has emerged that creating bridging systems based on cyanido ligands is a good and relatively simple way to create complex polymer structures exhibiting magnetic properties. Based on many years of personal experience in the field of the synthesis of polycyanido systems, supported by comprehensive structural analysis, a simple method of transforming cyanido complexes into soft ferromagnetic materials with a Curie temperature (TC) higher than the thermal decomposition temperature, usually above 150 °C has been developed. Two soft ferromagnetic materials based on zinc and cadmium hexacyanido salts in the system with [W(CN)6(bpy)]2−/− anions are presented. The crystal structures (X-ray single crystal as well as XRD) of the precursors and the properties of the ferromagnetic materials are discussed. Most importantly, a patented method of synthesizing this type of material, based on which we obtain more than 80 soft, high-temperature ferromagnetic compounds, which proves the wide spectrum of this method, is also presented.
Collapse
Affiliation(s)
- Janusz Szklarzewicz
- Faculty of Chemistry, Jagiellonian University, 30-387 Kraków, Poland; (M.H.); (A.J.)
- Correspondence:
| | - Maciej Hodorowicz
- Faculty of Chemistry, Jagiellonian University, 30-387 Kraków, Poland; (M.H.); (A.J.)
| | - Anna Jurowska
- Faculty of Chemistry, Jagiellonian University, 30-387 Kraków, Poland; (M.H.); (A.J.)
| | - Stanisław Baran
- M. Smoluchowski Institute of Physics, Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-001 Kraków, Poland;
| |
Collapse
|
23
|
Singh A, Price CC, Shenoy VB. Magnetic Order, Electrical Doping, and Charge-State Coupling at Amphoteric Defect Sites in Mn-Doped 2D Semiconductors. ACS Nano 2022; 16:9452-9460. [PMID: 35617052 DOI: 10.1021/acsnano.2c02387] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Two-dimensional (2D) dilute magnetic semiconductors (DMSs) are attractive material platforms for applications in multifunctional nanospintronics due to the prospect of embedding controllable magnetic order within nanoscale semiconductors. Identifying candidate host material and dopant systems requires consideration of doping formation energies, magnetic ordering, and the tendency for dopants to form clustered domains. In this work, we consider the defect thermodynamics and the dilute magnetic properties across charge states of 2D-MoS2 and 2D-WS2 with Mn magnetic dopants as candidate systems for 2D-DMSs. Using hybrid density functional calculations, we study the magnetic and electronic properties of these systems across configurations with thermodynamically favorable defects: 2D-MoS2 doped with Mn atoms at sulfur site (MnS), at two Mo sites (2MnMo), on top of a Mo atom (Mn-top), and at a Mo site (MnMo). While the majority of the Mn-defect complexes provide trap states, MnMo and MnW are amphoteric, although previously predicted to be donor defects. The impact of cluster formation of these amphoteric defects on magnetic ordering is also considered; both MnMo-MnMo (2Mn2Mo) and MnW-MnW (2Mn2W) clusters are found to be stable in ferromagnetic (FM) ordering. Interestingly, we observed the defect charge state dependent magnetic behavior of 2Mn2Mo and 2Mn2W clusters in 2D-TMDs. We investigate that the FM coupling of 2Mn2Mo and 2Mn2W clusters is stable in only a neutral charge state; however, the antiferromagnetic (AFM) coupling is stable in the +1 charge state. 2Mn2Mo clusters provide shallow donor levels in AFM coupling and deep donor levels in FM coupling. 2Mn2W clusters lead to trap states in the FM and AFM coupling. We demonstrate the AFM to FM phase transition at a critical electron density nce = 3.5 × 1013 cm-2 in 2D-MoS2 and 2D-WS2. At a 1.85% concentration of Mn, we calculate the Curie temperature of 580 K in the mean-field approximation.
Collapse
Affiliation(s)
- Akash Singh
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Christopher C Price
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Vivek B Shenoy
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| |
Collapse
|
24
|
Chakraborty S, Nalupurackal G, Gunaseelan M, Roy S, Lokesh M, Goswami J, Datta P, Mahapatra PS, Roy B. Facets of optically and magnetically induced heating in ferromagnetically doped-NaYF 4 particles. J Phys Commun 2022; 7:065008. [PMID: 37398924 PMCID: PMC7614712 DOI: 10.1088/2399-6528/acde43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Upconverting particles like Yb and Er-doped NaYF4 are known to heat up after illumination with light at pump wavelength due to inefficient upconversion processes. Here we show that NaYF4 particles which have been co-doped not only with Yb and Er but also Fe improves the photothermal conversion efficiency. In addition, we show for the first time that alternating magnetic fields also heat up the ferromagnetic particles. Thereafter we show that a combination of optical and magnetic stimuli significantly increases the heat generated by the particles.
Collapse
Affiliation(s)
- Snigdhadev Chakraborty
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-group, Micro Nano and Bio-Fluidics (MNBF)-Group, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Gokul Nalupurackal
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-group, Micro Nano and Bio-Fluidics (MNBF)-Group, Indian Institute of Technology Madras, Chennai, 600036, India
| | - M Gunaseelan
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-group, Micro Nano and Bio-Fluidics (MNBF)-Group, Indian Institute of Technology Madras, Chennai, 600036, India
- Department of Physics, Rathinam Research Hub, Rathinam College of Arts and Science, Coimbatore, 641021, India
| | - Srestha Roy
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-group, Micro Nano and Bio-Fluidics (MNBF)-Group, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Muruga Lokesh
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-group, Micro Nano and Bio-Fluidics (MNBF)-Group, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Jayesh Goswami
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-group, Micro Nano and Bio-Fluidics (MNBF)-Group, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Priyankan Datta
- Department of Mechanical engineering, Indian Institute of Technology Madras, India
| | | | - Basudev Roy
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-group, Micro Nano and Bio-Fluidics (MNBF)-Group, Indian Institute of Technology Madras, Chennai, 600036, India
| |
Collapse
|
25
|
Kumar S, Ahmed F, Ahmad N, Shaalan NM, Kumar R, Alshoaibi A, Arshi N, Dalela S, Albossed M, Chae KH, Alvi PA, Kumari K. Role of Cr Doping on the Structure, Electronic Structure, and Electrochemical Properties of BiFeO 3 Nanoparticles. Materials (Basel) 2022; 15:ma15124118. [PMID: 35744177 PMCID: PMC9227576 DOI: 10.3390/ma15124118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 05/25/2022] [Accepted: 06/07/2022] [Indexed: 12/10/2022]
Abstract
BiFe1−xCrxO3, (0 ≤ x ≤ 10) nanoparticles were prepared through the sol−gel technique. The synthesized nanoparticles were characterized using various techniques, viz., X-ray diffraction, high-resolution field emission scanning electron microscopy (HRFESEM), energy dispersive spectroscopy (EDS), UV−Vis absorption spectroscopy, photoluminescence (PL), dc magnetization, near-edge X-ray absorption spectroscopy (NEXAFS) and cyclic voltammetry (CV) measurements, to investigate the structural, morphological, optical, magnetic and electrochemical properties. The structural analysis showed the formation of BiFeO3 with rhombohedral (R3c) as the primary phase and Bi25FeO39 as the secondary phase. The secondary phase percentage was found to reduce with increasing Cr content, along with reductions in crystallite sizes, lattice parameters and enhancement in strain. Nearly spherical shape morphology was observed via HRFESEM with Bi, Fe, Cr and O as the major contributing elements. The bandgap reduced from 1.91 to 1.74 eV with the increase in Cr concentration, and PL spectra revealed emissions in violet, blue and green regions. The investigation of magnetic field (H)-dependent magnetization (M) indicated a significant effect of Cr substitution on the magnetic properties of the nanoparticles. The ferromagnetic character of the samples was found to increase with the increase in the Cr concentration and the increase in the saturation magnetization. The Fe (+3/+4) was dissolved in mixed-valence states, as found through NEXAFS analysis. Electrochemical studies showed that 5%-Cr-doped BFO electrode demonstrated outstanding performance for supercapacitors through a specific capacitance of 421 F g−1 measured with a scan rate of 10 mV s−1. It also demonstrated remarkable cyclic stability through capacitance retention of >78% for 2000 cycles.
Collapse
Affiliation(s)
- Shalendra Kumar
- Department of Physics, College of Science, King Faisal University, P.O. Box 400, Al-Ahsa 31982, Saudi Arabia; (F.A.); (N.M.S.); (A.A.); (M.A.)
- Department of Physics, University of Petroleum & Energy Studies, Dehradun 248007, India
- Correspondence:
| | - Faheem Ahmed
- Department of Physics, College of Science, King Faisal University, P.O. Box 400, Al-Ahsa 31982, Saudi Arabia; (F.A.); (N.M.S.); (A.A.); (M.A.)
| | - Naushad Ahmad
- Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia;
| | - Nagih M. Shaalan
- Department of Physics, College of Science, King Faisal University, P.O. Box 400, Al-Ahsa 31982, Saudi Arabia; (F.A.); (N.M.S.); (A.A.); (M.A.)
- Physics Department, Faculty of Science, Assiut University, Assiut 71516, Egypt
| | - Rajesh Kumar
- University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, New Delhi 110078, India;
| | - Adil Alshoaibi
- Department of Physics, College of Science, King Faisal University, P.O. Box 400, Al-Ahsa 31982, Saudi Arabia; (F.A.); (N.M.S.); (A.A.); (M.A.)
| | - Nishat Arshi
- Department of Basic Sciences, Preparatory Year Deanship, King Faisal University, P.O. Box 400, Hofuf Al-Ahsa 31982, Saudi Arabia;
| | - Saurabh Dalela
- Department of Pure & Applied Physics, University of Kota, Kota 324005, India;
| | - Mohammed Albossed
- Department of Physics, College of Science, King Faisal University, P.O. Box 400, Al-Ahsa 31982, Saudi Arabia; (F.A.); (N.M.S.); (A.A.); (M.A.)
| | - Keun Hwa Chae
- Advanced Analysis Center, Korea Institute of Science and Technology, Seoul 136-791, Korea;
| | - Parvez Ahmad Alvi
- Department of Physics, Banasthali Vidyapith, Banasthali 304022, India;
| | - Kavita Kumari
- School of Materials Science and Engineering, Changwon National University, Changwon 51140, Korea;
| |
Collapse
|
26
|
Abstract
The realization of magnetic skyrmions in nanostructures holds great promise for both fundamental research and device applications. Despite recent progress, intrinsic magnetic skyrmions in two-dimensional lattice are still rarely explored. Here, using first-principles calculations and Monte Carlo simulations, we report the identification of spontaneous magnetic skyrmions in single-layer CrInX3 (X = Te, Se). Because of the joint effect of broken inversion symmetry and strong spin-orbit coupling, inherent large Dzyaloshinskii-Moriya interaction occurs in both systems, endowing the intriguing Néel-type skyrmions. By further imposing moderate magnetic field, the skyrmion phase can be obtained and is stable within a wide temperature range. Particularly for single-layer CrInTe3, the size of skyrmions is sub-10 nm and the skyrmion phase can be maintained at an elevated temperature of ∼180 K. In addition, the phase diagrams of their topological spin textures under the variation of magnetic parameters of D, J, and K are mapped out.
Collapse
Affiliation(s)
- Wenhui Du
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Street 27, Jinan 250100, China
| | - Kaiying Dou
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Street 27, Jinan 250100, China
| | - Zhonglin He
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Street 27, Jinan 250100, China
| | - Ying Dai
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Street 27, Jinan 250100, China
| | - Baibiao Huang
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Street 27, Jinan 250100, China
| | - Yandong Ma
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Street 27, Jinan 250100, China
| |
Collapse
|
27
|
Abstract
Magnetic materials have been applied in a large variety of technologies, from data storage to quantum devices. The development of two-dimensional (2D) materials has opened new arenas for magnetic compounds, even when classical theories discourage their examination. Here we propose a machine-learning-based strategy to predict and understand magnetic ordering in 2D materials. This strategy couples the prediction of the existence of magnetism in 2D materials using a random forest and the Shapley additive explanations method with material maps defined by atomic features predicting the magnetic ordering (ferromagnetic or antiferromagnetic). While the random forest model predicts magnetism with an accuracy of 86%, the material maps obtained by the sure independence screening and sparsifying method have an accuracy of ∼90% in predicting the magnetic ordering. Our model indicates that 3d transition metals, halides, and structural clusters with regular transition-metal sublattices have a positive contribution in the total weight deciding the existence of magnetism in 2D compounds. This behavior is associated with the competition between crystal field and exchange splitting. The machine learning model also indicates that the atomic spin orbit coupling (SOC) is a determinant feature for the identification of the patterns separating ferro- from antiferromagnetic order. The proposed strategy is used to identify novel 2D magnetic compounds that, together with the fundamental trends in the chemical and structural space, pave novel routes for experimental exploration.
Collapse
Affiliation(s)
| | - Elton Ogoshi
- Federal University of ABC, 09210-580 Santo André, São Paulo, Brazil
| | | | | |
Collapse
|
28
|
Zhang L, Tang C, Sanvito S, Gu Y, Du A. Hydrogen-Intercalated 2D Magnetic Bilayer: Controlled Magnetic Phase Transition and Half-Metallicity via Ferroelectric Switching. ACS Appl Mater Interfaces 2022; 14:1800-1806. [PMID: 34962753 DOI: 10.1021/acsami.1c21848] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Electrically controlled magnetism in two-dimensional (2D) multiferroics is highly desirable for both fundamental research and the future development of low-power nanodevices. Herein, inspired by the recently experimentally realized 2D antiferromagnetic MnPSe3 [ Nat. Nanotechnol. 2021, 16 (7), 782] and guided by a heteromagnetic structural design, we engineer strong magnetoelectric coupling in a hydrogen-intercalated 2D MnPSe3 bilayer. Hydrogen functionalization breaks the centrosymmetry of bilayer MnPSe3, leading to out-of-plane ferroelectricity. Moreover, there is a phase transition from antiferromagnetic semiconductor to ferromagnetic half-metal in the H-bonded MnPSe3 layer, while the other remains antiferromagnetic and semiconducting. When reversing the electrical polarization, the intercalated H atom can flip between the top and bottom layers with an ultralow switching barrier, which allows one to tune the magnetic order and conductivity of the individual layers via an external electric field. Our results pave a new avenue to realize strong magnetoelectric coupling in single-phase multiferroic material. The ferroelectricity-controlled magnetic phase transition and half-metallicity offer promising applications in nanoscale spintronics such as electrically written and magnetically read memories.
Collapse
Affiliation(s)
- Lei Zhang
- School of Chemistry and Physics, Queensland University of Technology, Gardens Point Campus, Brisbane, QLD 4000, Australia
- Centre for Materials Science, Queensland University of Technology, Gardens Point Campus, Brisbane, QLD 4000, Australia
| | - Cheng Tang
- School of Chemistry and Physics, Queensland University of Technology, Gardens Point Campus, Brisbane, QLD 4000, Australia
- Centre for Materials Science, Queensland University of Technology, Gardens Point Campus, Brisbane, QLD 4000, Australia
| | - Stefano Sanvito
- School of Physics and CRANN Institute, Trinity College, Dublin 2 D02 PN40, Ireland
| | - Yuantong Gu
- School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Gardens Point Campus, Brisbane, QLD 4000, Australia
| | - Aijun Du
- School of Chemistry and Physics, Queensland University of Technology, Gardens Point Campus, Brisbane, QLD 4000, Australia
- Centre for Materials Science, Queensland University of Technology, Gardens Point Campus, Brisbane, QLD 4000, Australia
| |
Collapse
|
29
|
Dawn R, Zzaman M, Faizal F, Kiran C, Kumari A, Shahid R, Panatarani C, Joni IM, Verma VK, Sahoo SK, Amemiya K, Singh VR. Origin of Magnetization in Silica-coated Fe 3O 4 Nanoparticles Revealed by Soft X-ray Magnetic Circular Dichroism. Braz J Phys 2022; 52:99. [PMCID: PMC9014780 DOI: 10.1007/s13538-022-01102-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 03/31/2022] [Indexed: 05/24/2023]
Abstract
Abstract
Magnetite (Fe3O4) nanoparticles (NPs) and SiO2-coated Fe3O4 nanoparticles have successfully been synthesized using co-precipitation and modified Stöber methods, respectively. The samples were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, high-resolution transmission electron microscopy (HRTEM), vibrating sample magnetometer (VSM) techniques, X-ray absorption spectroscopy (XAS), and X-ray magnetic circular dichroism (XMCD). XRD and FTIR data confirmed the structural configuration of a single-phase Fe3O4 and the successful formation of SiO2-coated Fe3O4 NPs. XRD also confirmed that we have succeeded to synthesize nano-meter size of Fe3O4 NPs. HRTEM images showed the increasing thickness of SiO2-coated Fe3O4 with the addition of the Tetraethyl Orthosilicate (TEOS). Room temperature VSM analysis showed the magnetic behaviour of Fe3O4 and its variations that occurred after SiO2 coating. The magnetic behaviour is further authenticated by XAS spectra analysis which cleared about the existence of SiO2 shells that have transformed the crystal as well as the local structures of the magnetite NPs. We have performed XMCD measurements, which is a powerful element-specific technique to find out the origin of magnetization in SiO2-coated Fe3O4 NPs, that verified a decrease in magnetization with increasing thickness of the SiO2 coating. Graphical Abstract Magnetite (Fe3O4) nanoparticles (NPs) and SiO2-coated Fe3O4 nanoparticles have successfully been synthesized using co-precipitation and modified Stöber methods, respectively. The samples were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, high-resolution transmission electron microscopy (HRTEM), vibrating sample magnetometer (VSM) techniques, X-ray absorption spectroscopy (XAS), and X-ray magnetic circular dichroism (XMCD). XRD and FTIR data confirmed the structural configuration of a single-phase Fe3O4 and the successful formation of SiO2-coated Fe3O4 NPs. XRD also confirmed that we have succeeded to synthesize nano-meter size of Fe3O4 NPs. HRTEM images showed the increasing thickness of SiO2-coated Fe3O4 with the addition of the Tetraethyl Orthosilicate (TEOS). Room temperature VSM analysis showed the magnetic behaviour of Fe3O4 and its variations that occurred after SiO2 coating. The magnetic behaviour is further authenticated by XAS spectra analysis which cleared about the existence of SiO2 shells that have transformed the crystal as well as the local structures of the magnetite NPs. We have performed XMCD measurements, which is a powerful element-specific technique to find out the origin of magnetization in SiO2-coated Fe3O4 NPs, that verified a decrease in magnetization with increasing thickness of the SiO2 coating. ![]()
Collapse
Affiliation(s)
- R. Dawn
- Department of Physics, Central University of South Bihar, Gaya-824236, India
| | - M. Zzaman
- Department of Physics, Central University of South Bihar, Gaya-824236, India
- Department of Physics, Jamia Millia Islamia (Central University), New Delhi, 110025 India
| | - F. Faizal
- Department of Physics, Universitas Padjadjaran, Jl. Raya Bandung-Sumedang Km 21, West Java, Bandung, 45363 Indonesia
- Functional Nano Powder University Centre of Excellence (FiNder U CoE), Universitas Padjadjaran, Jl. Raya Bandung-Sumedang, Km 21, West Java, Bandung, 45363 Indonesia
| | - C. Kiran
- Department of Animal Sciences, Central University of Kashmir, Ganderbal, 191201 India
| | - A. Kumari
- Department of Physics, Central University of South Bihar, Gaya-824236, India
| | - R. Shahid
- Department of Physics, Jamia Millia Islamia (Central University), New Delhi, 110025 India
| | - C. Panatarani
- Department of Physics, Universitas Padjadjaran, Jl. Raya Bandung-Sumedang Km 21, West Java, Bandung, 45363 Indonesia
- Functional Nano Powder University Centre of Excellence (FiNder U CoE), Universitas Padjadjaran, Jl. Raya Bandung-Sumedang, Km 21, West Java, Bandung, 45363 Indonesia
| | - I. M. Joni
- Department of Physics, Universitas Padjadjaran, Jl. Raya Bandung-Sumedang Km 21, West Java, Bandung, 45363 Indonesia
- Functional Nano Powder University Centre of Excellence (FiNder U CoE), Universitas Padjadjaran, Jl. Raya Bandung-Sumedang, Km 21, West Java, Bandung, 45363 Indonesia
| | - V. K. Verma
- Department of Physics, Madanapalle Institute of Technology & Science, Madanapalle, 517325 India
| | - S. K. Sahoo
- Department of Metallurgical and Materials Engineering, National Institute of Technology, Rourkela, 769008 India
| | - K. Amemiya
- Photon Factory, IMSS, High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801 Japan
| | - V. R. Singh
- Department of Physics, Central University of South Bihar, Gaya-824236, India
| |
Collapse
|
30
|
Blümler P. Magnetic Guiding with Permanent Magnets: Concept, Realization and Applications to Nanoparticles and Cells. Cells 2021; 10:2708. [PMID: 34685688 DOI: 10.3390/cells10102708] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/01/2021] [Accepted: 09/02/2021] [Indexed: 02/06/2023] Open
Abstract
The idea of remote magnetic guiding is developed from the underlying physics of a concept that allows for bijective force generation over the inner volume of magnet systems. This concept can equally be implemented by electro- or permanent magnets. Here, permanent magnets are in the focus because they offer many advantages. The equations of magnetic fields and forces as well as velocities are derived in detail and physical limits are discussed. The special hydrodynamics of nanoparticle dispersions under these circumstances is reviewed and related to technical constraints. The possibility of 3D guiding and magnetic imaging techniques are discussed. Finally, the first results in guiding macroscopic objects, superparamagnetic nanoparticles, and cells with incorporated nanoparticles are presented. The constructed magnet systems allow for orientation, movement, and acceleration of magnetic objects and, in principle, can be scaled up to human size.
Collapse
|
31
|
Guan Z, Ni S. Strain-Controllable High Curie Temperature, Large Valley Polarization, and Magnetic Crystal Anisotropy in a 2D Ferromagnetic Janus VSeTe Monolayer. ACS Appl Mater Interfaces 2020; 12:53067-53075. [PMID: 33175497 DOI: 10.1021/acsami.0c13988] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Two-dimensional (2D) intrinsic ferromagnetic semiconductors are important for spintronics. A highly stable ML (monolayer) Janus 2H-VSeTe with intrinsic ferromagnetism is investigated by density functional theory. The biaxial strain could effectively tune the magnetic and electronic properties of Janus VSeTe. Specifically, the magnetic moment, band gap, Curie temperature (Tc), and valley splitting (Δ) could be modulated, as the states near the Fermi level are mainly contributed by the in-plane atomic orbitals. The VSeTe could be switched from ferromagnetic (FM) order to antiferromagnetic (AFM) ground state, under biaxial strains. And the corresponding Tc is tuned from 360 K (4%) to 0 K (-10.7%). However, VSeTe can be modulated from bipolar magnetic semiconductor (BMS) to half-semiconductor (HSC), spin gapless semiconductor (SGS), half-metal (HM), and even normal metal as the biaxial strain varies from -13 to 10%. Moreover, the easy and hard axes could be switched from each other, and the magnetocrystalline anisotropy (MCA) energy is also controlled by the strains. The Δ is also increased from 158 to 169 meV as the strain varies from 3.3 to -3.0%. The magnetic and electronic phase transitions in the strained VSeTe are observed, which could help researchers to investigate the controllable electronic and magnetic properties in electronics, spintronics, and valleytronics.
Collapse
Affiliation(s)
- Zhaoyong Guan
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, P. R. China
- Science Center for Material Creation and Energy Conversion, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 266237, P. R. China
| | - Shuang Ni
- Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900, P. R. China
| |
Collapse
|
32
|
Gao F, Fan J, Zhang L, Chen B. Unraveling the Origin of Tribomagnetization in Ferromagnetic Materials. ACS Appl Mater Interfaces 2020; 12:50176-50186. [PMID: 33105994 DOI: 10.1021/acsami.0c15044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Tribomagnetization, a natural phenomenon known for decades, has many engineering applications today. However, its intrinsic origin remains controversial and the mechanistic-based model has not yet been developed to predict the tribomagnetization behavior. In this work, the origin of tribomagnetization is investigated via both the experimental and modeling approaches. For the first time, the expansion of surface plastic deformation to the subsurface layer (i.e., dislocation strain gradient) is characterized in conjunction with the tribological behavior of the interface. By performing the reciprocating sliding experiment in a pin-on-block contact configuration, the tribomagnetization evolution in different wear regimes is followed, the geometrically necessary dislocations (GNDs) developed in the subsurface are measured, and the formation of characteristic magnetic domains is revealed. A tribomagnetization model is proposed on the basis of the sliding-induced plastic deformation mechanism with GNDs, bringing the missing link with classical tribology and ferromagnetism. The model reveals that the surface plastic strain and width of a wear scar are two crucial factors in determining the surface magnetic field changes. We believe that the tribomagnetization originates from the magnetic distortion accompanied by the progression of GNDs in the subsurface. Our hypothesis is supported by the good agreement between the model prediction and experimental observation.
Collapse
Affiliation(s)
- F Gao
- China University of Petroleum-Beijing, Fuxue Road 18, Changping, Beijing 102249, P. R. China
- School of Engineering, University of Leicester, Leicester LE1 7RH, U.K
| | - J Fan
- China University of Petroleum-Beijing, Fuxue Road 18, Changping, Beijing 102249, P. R. China
| | - L Zhang
- China University of Petroleum-Beijing, Fuxue Road 18, Changping, Beijing 102249, P. R. China
| | - B Chen
- School of Engineering, University of Leicester, Leicester LE1 7RH, U.K
| |
Collapse
|
33
|
Bhugra VS, Hughson FR, Williams GVM, Chong SV, Nann T. Corrigendum: Electrospun, Oriented, Ferromagnetic Ni 1-x Fe x Nanofibers. Front Chem 2020; 8:809. [PMID: 33088804 PMCID: PMC7495133 DOI: 10.3389/fchem.2020.00809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 07/31/2020] [Indexed: 11/29/2022] Open
Affiliation(s)
- Vaibhav S Bhugra
- School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Fraser R Hughson
- School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Grant V M Williams
- School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Shen V Chong
- Robinson Research Institute, Victoria University of Wellington, Lower Hutt, New Zealand
| | - Thomas Nann
- School of Mathematical and Physical Sciences, The University of Newcastle, Newcastle, NSW, Australia
| |
Collapse
|
34
|
Li Q, Zhao X, Deng L, Shi Z, Liu S, Wei Q, Zhang L, Cheng Y, Zhang L, Lu H, Gao W, Huang W, Qiu CW, Xiang G, Pennycook SJ, Xiong Q, Loh KP, Peng B. Enhanced Valley Zeeman Splitting in Fe-Doped Monolayer MoS 2. ACS Nano 2020; 14:4636-4645. [PMID: 32167276 DOI: 10.1021/acsnano.0c00291] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The "Zeeman effect" offers unique opportunities for magnetic manipulation of the spin degree of freedom (DOF). Recently, valley Zeeman splitting, referring to the lifting of valley degeneracy, has been demonstrated in two-dimensional transition metal dichalcogenides (TMDs) at liquid helium temperature. However, to realize the practical applications of valley pseudospins, the valley DOF must be controllable by a magnetic field at room temperature, which remains a significant challenge. Magnetic doping in TMDs can enhance the Zeeman splitting; however, to achieve this experimentally is not easy. Here, we report unambiguous magnetic manipulation of valley Zeeman splitting at 300 K (geff = -6.4) and 10 K (geff = -11) in a CVD-grown Fe-doped MoS2 monolayer; the effective Landé geff factor can be tuned to -20.7 by increasing the Fe dopant concentration, which represents an approximately 5-fold enhancement as compared to undoped MoS2. Our measurements and calculations reveal that the enhanced splitting and geff factors are due to the Heisenberg exchange interaction of the localized magnetic moments (Fe 3d electrons) with MoS2 through the d-orbital hybridization.
Collapse
Affiliation(s)
- Qi Li
- National Engineering Research Center of Electromagnetic Radiation Control Materials, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China
| | - Xiaoxu Zhao
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575, Singapore
| | - Longjiang Deng
- National Engineering Research Center of Electromagnetic Radiation Control Materials, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China
| | - Zhongtai Shi
- National Engineering Research Center of Electromagnetic Radiation Control Materials, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China
| | - Sheng Liu
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Qilin Wei
- Key Laboratory of Flexible Electronics & Institute of Advanced Materials, Nanjing Tech University, Nanjing, 211816, China
| | - Linbo Zhang
- National Engineering Research Center of Electromagnetic Radiation Control Materials, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China
| | - Yingchun Cheng
- Key Laboratory of Flexible Electronics & Institute of Advanced Materials, Nanjing Tech University, Nanjing, 211816, China
| | - Li Zhang
- National Engineering Research Center of Electromagnetic Radiation Control Materials, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China
| | - Haipeng Lu
- National Engineering Research Center of Electromagnetic Radiation Control Materials, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China
| | - Weibo Gao
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Wei Huang
- Key Laboratory of Flexible Electronics & Institute of Advanced Materials, Nanjing Tech University, Nanjing, 211816, China
| | - Cheng-Wei Qiu
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583, Singapore
| | - Gang Xiang
- College of Physical Science and Technology, Sichuan University, Chengdu, 610064, China
| | - Stephen John Pennycook
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575, Singapore
| | - Qihua Xiong
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Kian Ping Loh
- Department of Chemistry and Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore 117549, Singapore
| | - Bo Peng
- National Engineering Research Center of Electromagnetic Radiation Control Materials, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China
| |
Collapse
|
35
|
Abstract
Electrospinning has been used to fabricate ferromagnetic Ni0.47Fe0.53 nanofiber mats that were composed of individual, orientated Ni0.47Fe0.53 nanofibers. The key steps were processing a polyvinylpyrrolidone nanofiber template containing ferric nitrate and nickel acetate metal precursors in Ar at 300°C and then 95% Ar: 5% H2 at 600°C. The Ni0.47Fe0.53 fibers were nanostructured and contained Ni0.47Fe0.53 nanocrystals with average diameters of ~14 nm. The Ni0.47Fe0.53 ferromagnetic mats had a high saturation magnetic moment per formula unit that was comparable to those reported in other studies of nanostructured Ni1-xFex. There is a small spin-disordered fraction that is typically seen in nanoscale ferromagnets and is likely to be caused by the surface of the nanofibers. There was an additional magnetic contribution that could possibly stem from a small Fe1-zNizO phase fraction surrounding the fibers. The coercivity was found to be enhanced when compared with the bulk material.
Collapse
Affiliation(s)
- Vaibhav S Bhugra
- School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Grant V M Williams
- School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Shen V Chong
- Robinson Research Institute, Victoria University of Wellington, Lower Hutt, New Zealand
| | - Thomas Nann
- School of Mathematical and Physical Sciences, The University of Newcastle, Newcastle, NSW, Australia
| |
Collapse
|
36
|
Van Dyck L, Bentouhami H, Koch K, Samson R, Weyler J. Exposure to Indoor Ferromagnetic Particulate Matter Monitored by Strawberry Plants and the Occurrence of Acute Respiratory Events in Adults. Int J Environ Res Public Health 2019; 16:E4823. [PMID: 31801242 DOI: 10.3390/ijerph16234823] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 11/07/2019] [Accepted: 11/25/2019] [Indexed: 11/22/2022]
Abstract
Exposure assessment of air pollution in epidemiologic research remains a challenge. Previous studies showed that magnetic monitoring of strawberry leaves, based on Saturation Isothermal Remnant Magnetization (SIRM), is a valid tool for estimating the concentration of ambient particulate matter (PM). This study uses this assessment method for the first time in epidemiologic research to quantify indoor exposure to PM. In a nested case control study, we evaluated the association between ‘waking up by cough’ and indoor air pollution measured by SIRM of dust deposition on leaves of strawberry plants located in the bedroom in the general adult population. A multiple logistic regression was used to estimate the association between ‘waking up by cough’ and exposure to ferromagnetic particles of PM controlling for age, gender and smoking status. A cut-off of 10 µA was decided to define exposure status (high versus low). Using logistic regression, a crude odds ratio (OR) of 1.80 (95% CI: 0.90–3.60) for ‘waking up by cough’ was found. This association remained approximately the same after controlling for age, gender and smoking status (adjusted OR: 1.76; 95% CI: 0.60–5.30). We found an association between exposure to ferromagnetic particles and ‘waking up by cough’ in adults; however, it was not statistically significant. This environmental exposure assessment method could be a valuable alternative for expensive personal exposure measurement devices.
Collapse
|
37
|
Van Kerckhoven V, Piraux L, Huynen I. Fabrication of Microwave Devices Based on Magnetic Nanowires Using a Laser-Assisted Process. Micromachines (Basel) 2019; 10:E475. [PMID: 31315239 DOI: 10.3390/mi10070475] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 07/07/2019] [Accepted: 07/12/2019] [Indexed: 11/17/2022]
Abstract
This paper compares two laser-assisted processes developed by the authors for the fabrication of microwave devices based on nanowire arrays loaded inside porous alumina templates. Pros and cons of each process are discussed in terms of accuracy, reproducibility and ease of fabrication. A comparison with lithography technique is also provided. The efficiency of the laser-assisted process is demonstrated through the realization of substrate integrated waveguide (SIW) based devices. A Nanowired SIW line is firstly presented. It operates between 8.5 and 17 GHz, corresponding to the first and second cut-off frequency of the waveguide, respectively. Next, a Nanowired SIW isolator is demonstrated. It shows a nonreciprocal isolation of 12 dB (corresponding to 4.4 dB/cm), observed in absence of a DC magnetic field, and achieved through an adequate positioning of ferromagnetic nanowires inside the waveguide cavity.
Collapse
|
38
|
Zhang J, Fang C, Weng GJ. Direct and converse nonlinear magnetoelectric coupling in multiferroic composites with ferromagnetic and ferroelectric phases. Proc Math Phys Eng Sci 2019; 475:20190002. [PMID: 31236051 DOI: 10.1098/rspa.2019.0002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Accepted: 04/25/2019] [Indexed: 11/12/2022] Open
Abstract
In this paper, we develop a theoretical principle to calculate the direct and converse magnetoelectric (ME) coupling response of ferromagnetic/ferroelectric composites with 2-2 connectivity. We first present an experimentally based constitutive equation for Terfenol-D, and then build the mechanism of domain switch for the ferroelectric phase. In the latter, the change of Gibbs free energy, thermodynamic driving force and kinetic equations for domain growth are also established. These two sets of constitutive equations are shown to capture the experimental data of Terfenol-D and PZT, respectively, well. For the direct effect under an applied magnetic field, the induced electric field and the overall ME coupling coefficient are determined. For the converse effect under an applied electric field, the induced magnetization and the excited magnetic field are obtained. Both the induced electric filed under direct effect and the excited magnetic field under converse effect are shown to display the hysteretic characteristics, and also in good agreement with experiments. We conclude that the developed theory can both qualitatively and quantitatively reflect the essential features of nonlinear direct and converse ME coupling of the multiferroic composites.
Collapse
Affiliation(s)
- Juanjuan Zhang
- Key Laboratory of Mechanics on Environment and Disaster in Western China, The Ministry of Education of China, Lanzhou University, Lanzhou, Gansu 730000, People's Republic of China.,Department of Mechanics and Engineering Science, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, Gansu 730000, People's Republic of China.,Department of Mechanical and Aerospace Engineering, Rutgers University, New Brunswick, NJ 08903, USA
| | - Chao Fang
- Department of Electrical and Electronic Engineering, Wuhan Polytechnic University, Wuhan, Hubei 430023, People's Republic of China.,Department of Mechanical and Aerospace Engineering, Rutgers University, New Brunswick, NJ 08903, USA
| | - George J Weng
- Department of Mechanical and Aerospace Engineering, Rutgers University, New Brunswick, NJ 08903, USA
| |
Collapse
|
39
|
Rosales-González O, Sánchez-De Jesús F, Pedro-García F, Cortés-Escobedo CA, Ramírez-Cardona M, Bolarín-Miró AM. Enhanced Multiferroic Properties of YFeO 3 by Doping with Bi 3. Materials (Basel) 2019; 12:E2054. [PMID: 31247978 DOI: 10.3390/ma12132054] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 06/20/2019] [Accepted: 06/25/2019] [Indexed: 11/17/2022]
Abstract
Tthe present work studied the cationic substitution of Y3+ by Bi3+ on the crystal structure of orthorhombic YFeO3 and its effect over magnetic, dielectric and electric properties of multiferroic yttrium orthoferrite. Stoichiometric mixtures of Y2O3, Fe2O3 and Bi2O3 were mixed and milled for 5 h using a ball to powder weight ratio of 10:1 by high-energy ball milling. The obtained powders were pressed at 1500 MPa and sintered at 700 °C for 2 h. The test samples were characterized at room temperature by X-ray diffraction (XRD), vibrating sample magnetometer (VSM), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS) and impedance spectroscopy (IS). The X-ray diffraction patterns disclosed a maximum solubility of 30 % mol. of Bi3+ into the orthorhombic YFeO3. For higher concentrations, a transformation from orthorhombic to garnet structure was produced, obtaining partially Y3Fe5O12 phase. The substitution of Bi3+ in Y3+ sites promoted a distortion into the orthorhombic structure and modified Fe-O-Fe angles and octahedral tilt. In addition, it promoted a ferromagnetic (FM) order, which was attributed to both the crystal distortion and Dzyaloshinskii-Moriya interaction. For doped samples, an increase in real permittivity values was observed, and reduced with the increase of frequency. This in good agreement with the Maxwell-Wagner effect.
Collapse
|
40
|
Yu HC, Lin CH, Yang CI. Temperature-Controlled Assembly/Reassembly of Two Dicarboxylate-Based Three-Dimensional Co(II) Coordination Polymers with an Anti ferromagnetic Metallic Layer and a Ferromagnetic Metallic Chain. Polymers (Basel) 2019; 11:E795. [PMID: 31052601 DOI: 10.3390/polym11050795] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Revised: 04/28/2019] [Accepted: 04/30/2019] [Indexed: 11/17/2022] Open
Abstract
Two new dicarboxylate-based three-dimensional cobalt coordination polymers, [Co(Me2mal)(bpe)0.5(H2O)]n (1) and [Co(Me2mal)(bpe)0.5]n (2), were synthesized from dimethylmalonic acid (H2-Me2mal) in temperature-controlled solvothermal reactions. Lower temperatures (6080 °C) favored the formation of 1, while higher temperatures (120 °C) favored the production of 2. Compound 1 is comprised of Co(II) corrugated layers linked by syn-anti carboxylate bridges from the Me2mal2- ligands and pillared through bis-monodentate bpe groups. Compound 2 is comprised of a three-dimensional network involving one-dimensional Co-carboxylate chains bonded by antisymmetric µ4-Me2mal2- ligands and aligned parallel to the [001] direction. The solvothermal retreatment of crystalline samples of 1 in a DMF/H2O solvent at 120 °C allowed the structural reassembly, with complete conversion within 2 over 48 h. Magnetic analyses revealed that compound 1 exhibits both spin-orbital coupling and antiferromagnetic interactions through a syn-anti carboxylate (Me2mal2-) bridge exchange pathway [Co-Co separation of 5.478 Å] and compound 2 showed a ferromagnetic interaction resulting from the short Co-Co separation (3.150 Å) and the small Co-O-Co bridging angles (98.5° and 95.3°) exchange pathway which was provided by µ4-Me2mal2- bridging ligand.
Collapse
|
41
|
Zhang Y, Chu J, Yin L, Shifa TA, Cheng Z, Cheng R, Wang F, Wen Y, Zhan X, Wang Z, He J. Ultrathin Magnetic 2D Single-Crystal CrSe. Adv Mater 2019; 31:e1900056. [PMID: 30920696 DOI: 10.1002/adma.201900056] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 03/07/2019] [Indexed: 06/09/2023]
Abstract
2D magnetic materials have generated an enormous amount of attention due to their unique 2D-limited magnetism and their potential applications in spintronic devices. Recently, most of this research has focused on 2D van der Waals layered magnetic materials exfoliated from the bulk with random size and thicknesses. Controllable growth of these materials is still a great challenge. In contrast, 2D nonlayered magnetic materials have rarely been investigated, not especially regarding their preparation. Crn X (X = S, Se and Te; 0 < n < 1), a class of nonlayered transition metal dichalcogenides, has rapidly attracted extensive attention due to its abundance of structural compounds and unique magnetic properties. Herein, the controlled synthesis of ultrathin CrSe crystals, with grain size reaching the sub-millimeter scale, on mica substrates via an ambient pressure chemical vapor deposition (CVD) method is demonstrated. A continuous CrSe film can also be achieved via precise control of the key growth parameters. Importantly, the CVD-grown 2D CrSe crystals possess obvious ferromagnetic properties at temperatures below 280 K, which has not been observed experimentally before. This work broadens the scope of the CVD growth of 2D magnetic materials and highlights their significant application possibilities in spintronics.
Collapse
Affiliation(s)
- Yu Zhang
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Junwei Chu
- State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Lei Yin
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Science, Beijing, 100049, China
| | - Tofik Ahmed Shifa
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Zhongzhou Cheng
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Ruiqing Cheng
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Science, Beijing, 100049, China
| | - Feng Wang
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Yao Wen
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Science, Beijing, 100049, China
| | - Xueying Zhan
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Zhenxing Wang
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Science, Beijing, 100049, China
| | - Jun He
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Science, Beijing, 100049, China
| |
Collapse
|
42
|
Kong T, Stolze K, Timmons EI, Tao J, Ni D, Guo S, Yang Z, Prozorov R, Cava RJ. VI 3 -a New Layered Ferromagnetic Semiconductor. Adv Mater 2019; 31:e1808074. [PMID: 30843286 DOI: 10.1002/adma.201808074] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 02/05/2019] [Indexed: 06/09/2023]
Abstract
2D materials are promising candidates for next-generation electronic devices. In this regime, insulating 2D ferromagnets, which remain rare, are of special importance due to their potential for enabling new device architectures. Here the discovery of ferromagnetism is reported in a layered van der Waals semiconductor, VI3 , which is based on honeycomb vanadium layers separated by an iodine-iodine van der Waals gap. It has a BiI3 -type structure ( R 3 ¯ , No.148) at room temperature, and the experimental evidence suggests that it may undergo a subtle structural phase transition at 78 K. VI3 becomes ferromagnetic at 49 K, below which magneto-optical Kerr effect imaging clearly shows ferromagnetic domains, which can be manipulated by the applied external magnetic field. The optical bandgap determined by reflectance measurements is 0.6 eV, and the material is highly resistive.
Collapse
Affiliation(s)
- Tai Kong
- Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| | - Karoline Stolze
- Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| | - Erik I Timmons
- Ames Laboratory, US DOE, Department of Physics and Astronomy, Iowa State University, Ames, IA, 50011, USA
| | - Jing Tao
- Department of Physics, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Danrui Ni
- Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| | - Shu Guo
- Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| | - Zoë Yang
- Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| | - Ruslan Prozorov
- Ames Laboratory, US DOE, Department of Physics and Astronomy, Iowa State University, Ames, IA, 50011, USA
| | - Robert J Cava
- Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| |
Collapse
|
43
|
Zhang C, Nie Y, Sanvito S, Du A. First-Principles Prediction of a Room-Temperature Ferromagnetic Janus VSSe Monolayer with Piezoelectricity, Ferroelasticity, and Large Valley Polarization. Nano Lett 2019; 19:1366-1370. [PMID: 30648394 DOI: 10.1021/acs.nanolett.8b05050] [Citation(s) in RCA: 102] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Inspired by recent experiments on the successful fabrication of monolayer Janus transition-metal dichalcogenides [ Lu , A.-Y. ; Nat. Nanotechnol. 2017 , 12 , ( 8 ), 744 and ferromagnetic VSe2 [ Bonilla , M. ; Nat. Nanotechnol. 2018 , 13 , ( 4 ), 289 ], we predict a highly stable room-temperature ferromagnetic Janus monolayer (VSSe) by density functional theory methods and further confirmed the stability by a global minimum search with the particle-swarm optimization method. The VSSe monolayer exhibits a large valley polarization due to the broken space- and time-reversal symmetry. Moreover, its low symmetry C3 v point group results in giant in-plane piezoelectric polarization. Most interestingly, a strain-driven 90° lattice rotation is found in the magnetic VSSe monolayer with an extremely high reversal strain (73%), indicating an intrinsic ferroelasticity. The combination of piezoelectricity and valley polarization make magnetic 2D Janus VSSe a tantalizing material for potential applications in nanoelectronics, optoelectronics, and valleytronics.
Collapse
Affiliation(s)
- Chunmei Zhang
- School of Chemistry, Physics and Mechanical Engineering , Queensland University of Technology , Gardens Point Campus, Brisbane QLD 4001 , Australia
| | - Yihan Nie
- School of Chemistry, Physics and Mechanical Engineering , Queensland University of Technology , Gardens Point Campus, Brisbane QLD 4001 , Australia
| | - Stefano Sanvito
- School of Physics, AMBER and CRANN Institute , Trinity College , Dublin 2 , Ireland
| | - Aijun Du
- School of Chemistry, Physics and Mechanical Engineering , Queensland University of Technology , Gardens Point Campus, Brisbane QLD 4001 , Australia
| |
Collapse
|
44
|
Huang J, Wang H, Sun X, Zhang X, Wang H. Multifunctional La 0.67Sr 0.33MnO 3 (LSMO) Thin Films Integrated on Mica Substrates toward Flexible Spintronics and Electronics. ACS Appl Mater Interfaces 2018; 10:42698-42705. [PMID: 30427171 DOI: 10.1021/acsami.8b16626] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Integrating oxide thin films on flexible substrates is a critical step toward future applications of multifunctional oxides for flexible electronics and spintronic devices. As a demonstration, multifunctional La0.67Sr0.33MnO3 (LSMO) thin films have been deposited on flexible mica substrates. The crystallinity and microstructure of the films have been characterized to show the good epitaxial quality of the films. The LSMO thin films on mica present excellent ferromagnetic and magnetoresistance properties (such as saturation magnetization Ms of 125-400 emu/cm3 at 10 K and a high MR value of ∼45% at 5 K under 1 T for the 50 mTorr deposited sample), which is even better than the ones on conventional rigid single-crystal oxide substrates. More interestingly, no deterioration of the properties is observed under mechanically bending condition, which demonstrates the good mechanical stretchability and property stability of the LSMO thin films on mica. The demonstration of functional oxides integrated on flexible mica substrates paves a route toward future flexible spintronics and electronics.
Collapse
|
45
|
Guo M, Liu Y, Dong S, Jiao X, Wang T, Chen D. Co 9 S 8 -Catalyzed Growth of Thin-Walled Graphite Microtubes for Robust, Efficient Overall Water Splitting. ChemSusChem 2018; 11:4150-4155. [PMID: 30303629 DOI: 10.1002/cssc.201802055] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 10/06/2018] [Indexed: 06/08/2023]
Abstract
Co9 S8 crystals can catalyze the growth of thin-walled graphite microtubes (GMTs) through a catalytic chemical vapor deposition (CCVD) process using thiourea as the precursor. The growth of GMTs follows a tip-growth mechanism with tube diameters up to a few micrometer. The hollow interiors of the GMTs are filled with carbon nanotubes and wrinkled graphene layers, which form a unique nanotube/graphene-in-microtube structure. As-formed GMTs are N,S-codoped with lots of Co9 S8 nanoparticles encapsulated in their inner walls. These GMTs are room-temperature ferromagnets and can be loaded on Ni foams to work as binder-free electrocatalysts with low overpotential (310 mV at 50 mA cm-2 for the oxygen evolution reaction (OER) and 284 mV at 50 mA cm-2 for the hydrogen evolution reaction (HER)) and long-term durability (continuous work for 120 h without loss in performance). Our research proves that metal sulfides can catalyze the growth of graphite microtubes and as-formed GMTs may potentially be used as functional building blocks to construct new kinds of electrochemical devices for various energy-related applications.
Collapse
Affiliation(s)
- Mingrui Guo
- School of Chemistry & Chemical Engineering, National Engineering Research Center for Colloidal Materials, Shandong University, Jinan, 250100, P. R. China
| | - Yi Liu
- School of Chemistry & Chemical Engineering, National Engineering Research Center for Colloidal Materials, Shandong University, Jinan, 250100, P. R. China
| | - Shun Dong
- School of Chemistry & Chemical Engineering, National Engineering Research Center for Colloidal Materials, Shandong University, Jinan, 250100, P. R. China
| | - Xiuling Jiao
- School of Chemistry & Chemical Engineering, National Engineering Research Center for Colloidal Materials, Shandong University, Jinan, 250100, P. R. China
| | - Ting Wang
- School of Chemistry & Chemical Engineering, National Engineering Research Center for Colloidal Materials, Shandong University, Jinan, 250100, P. R. China
| | - Dairong Chen
- School of Chemistry & Chemical Engineering, National Engineering Research Center for Colloidal Materials, Shandong University, Jinan, 250100, P. R. China
| |
Collapse
|
46
|
Abstract
While the ferromagnetic properties of metallic objects, implantable medical devices, and cosmetics are well known, sand is not generally considered a consequential substance. Beaches in specific geographic regions, including the San Francisco Bay Area, have a propensity for ferromagnetic sand because of their geologic history. We describe a case in which ferromagnetic sand in a patient's hair coated the magnetic resonance imaging (MRI) scanner bore and caused significant imaging artifact, fortunately with no harm to the patient. We recommend that MRI facilities in areas where ferromagnetic sand is found consider educating technologists and screening patients for recent black sand exposure prior to scanning.
Collapse
Affiliation(s)
- Emil Jernstedt Barkovich
- 1 West Virginia University Health Sciences Center; George Washington University School of Medicine and Health Sciences; Children's National Health System, Department of Radiology, USA
| | - Matthew Jernstedt Barkovich
- 2 University of California San Francisco Medical Center at Parnassus, Department of Radiology and Biomedical Imaging, USA
| | - Christopher Hess
- 2 University of California San Francisco Medical Center at Parnassus, Department of Radiology and Biomedical Imaging, USA.,3 UCSF Benioff Children's Hospital, USA
| |
Collapse
|
47
|
Guo J, Cao T, Cheng C, Meng X, Zhao J. The Relationship Between Magnetism and Microstructure of Ethylene Pyrolysis Furnace Tubes after a Long-term Service. Microsc Microanal 2018; 24:478-487. [PMID: 30334517 DOI: 10.1017/s1431927618015180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The magnetism and microstructure of Cr25Ni35Nb and Cr35Ni45Nb alloy tubes after 5 years of service were investigated in this paper. The saturation magnetization of the Cr25Ni35Nb alloy tube in the thickness direction is more than 20 emu/g, and the tube becomes ferromagnetic. The inner and outer walls of Cr35Ni45Nb alloy tubes also become ferromagnetic. But the saturation magnetization of the Cr35Ni45Nb alloy tubes approaches to zero in the center zone. The primary carbides M7C3 and NbC are changed into M23C6 and G phase at the outer region of the furnace tube. However, the M23C6-type carbides were replaced by carbon-rich carbides M7C3 at the carburization zone. Cr-depleted zones are formed at the inner and outer walls of the furnace tubes owing to oxidation. Carburization and oxidation reduce the Cr content of the matrix. Accordingly, the saturation magnetization is very high at the carburization zone and Cr-depleted zone. The magnetism of Cr25Ni35Nb and Cr35Ni45Nb alloy tubes has a high correlation with the Cr content of the matrix. Carburization and oxidation are the main reasons that make the paramagnetic ethylene pyrolysis furnace tube change to ferromagnetic.
Collapse
Affiliation(s)
- Jingfeng Guo
- 1School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China
| | - Tieshan Cao
- 1School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China
| | - Congqian Cheng
- 1School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China
| | - Xianming Meng
- 2China Automotive Technology & Research Center,Tianjin 300300,China
| | - Jie Zhao
- 1School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China
| |
Collapse
|
48
|
Tan L, Liu B, Siemensmeyer K, Glebe U, Böker A. Synthesis of Polystyrene-Coated Superparamagnetic and Ferromagnetic Cobalt Nanoparticles. Polymers (Basel) 2018; 10:E1053. [PMID: 30960978 DOI: 10.3390/polym10101053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 09/13/2018] [Accepted: 09/18/2018] [Indexed: 01/15/2023] Open
Abstract
Polystyrene-coated cobalt nanoparticles (NPs) were synthesized through a dual-stage thermolysis of cobalt carbonyl (Co2(CO)8). The amine end-functionalized polystyrene surfactants with varying molecular weight were prepared via atom-transfer radical polymerization technique. By changing the concentration of these polymeric surfactants, Co NPs with different size, size distribution, and magnetic properties were obtained. Transmission electron microscopy characterization showed that the size of Co NPs stabilized with lower molecular weight polystyrene surfactants (Mn = 2300 g/mol) varied from 12–22 nm, while the size of Co NPs coated with polystyrene of middle (Mn = 4500 g/mol) and higher molecular weight (Mn = 10,500 g/mol) showed little change around 20 nm. Magnetic measurements revealed that the small cobalt particles were superparamagnetic, while larger particles were ferromagnetic and self-assembled into 1-D chain structures. Thermogravimetric analysis revealed that the grafting density of polystyrene with lower molecular weight is high. To the best of our knowledge, this is the first study to obtain both superparamagnetic and ferromagnetic Co NPs by changing the molecular weight and concentration of polystyrene through the dual-stage decomposition method.
Collapse
|
49
|
Medranda D, Borowiec J, Zhang X, Wang S, Yan K, Zhang J, He Y, Ivaturi S, Boi FS. Ferromagnetically filled carbon nano-onions: the key role of sulfur in dimensional, structural and electric control. R Soc Open Sci 2018; 5:170981. [PMID: 29410810 PMCID: PMC5792887 DOI: 10.1098/rsos.170981] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 12/01/2017] [Indexed: 06/08/2023]
Abstract
A key challenge in the fabrication of ferromagnetically filled carbon nano-onions (CNOs) is the control of their thickness, dimensions and electric properties. Up to now literature works have mainly focused on the encapsulation of different types of ferromagnetic materials including α-Fe, Fe3C, Co, FeCo, FePd3 and others within CNOs. However, no report has yet shown a suitable method for controlling both the number of shells, diameter and electric properties of the produced CNOs. Here, we demonstrate an advanced chemical vapour deposition approach in which the use of small quantities of sulfur during the pyrolysis of ferrocene allows for the control of (i) the diameter of the CNOs, (ii) the number of shells and (iii) the electric properties. We demonstrate the morphological, structural, electric and magnetic properties of these new types of CNOs by using SEM, XRD, TEM, HRTEM, EIS and VSM techniques.
Collapse
Affiliation(s)
- D. Medranda
- College of Physical Science and Technology, Sichuan University, Chengdu, People's Republic of China
| | - J. Borowiec
- College of Physical Science and Technology, Sichuan University, Chengdu, People's Republic of China
| | - Xiao Zhang
- College of Physical Science and Technology, Sichuan University, Chengdu, People's Republic of China
| | - S. Wang
- Analytical and Testing Centre, Sichuan University, Chengdu, People's Republic of China
| | - K. Yan
- School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - J. Zhang
- School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Y. He
- Analytical and Testing Centre, Sichuan University, Chengdu, People's Republic of China
| | - S. Ivaturi
- College of Physical Science and Technology, Sichuan University, Chengdu, People's Republic of China
| | - F. S. Boi
- College of Physical Science and Technology, Sichuan University, Chengdu, People's Republic of China
| |
Collapse
|
50
|
Sreenivasulu G, Zhang J, Zhang R, Popov M, Petrov V, Srinivasan G. Multiferroic Core-Shell Nanofibers, Assembly in a Magnetic Field, and Studies on Magneto-Electric Interactions. Materials (Basel) 2017; 11:E18. [PMID: 29295512 DOI: 10.3390/ma11010018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Revised: 12/18/2017] [Accepted: 12/20/2017] [Indexed: 12/03/2022]
Abstract
Ferromagnetic–ferroelectric nanocomposites are of interest for realizing strong strain-mediated coupling between electric and magnetic subsystems due to a high surface area-to-volume ratio. This report is on the synthesis of nickel ferrite (NFO)–barium titanate (BTO) core–shell nanofibers, magnetic field assisted assembly into superstructures, and studies on magneto-electric (ME) interactions. Electrospinning techniques were used to prepare coaxial fibers of 0.5–1.5 micron in diameter. The core–shell structure of annealed fibers was confirmed by electron microscopy and scanning probe microscopy. The fibers were assembled into discs and films in a uniform magnetic field or in a field gradient. Studies on ME coupling in the assembled films and discs were done by magnetic field (H)-induced polarization, magneto–dielectric effects at low frequencies and at 16–24 GHz, and low-frequency ME voltage coefficients (MEVC). We measured ~2–7% change in remnant polarization and in the permittivity for H = 7 kOe, and a MEVC of 0.4 mV/cm Oe at 30 Hz. A model has been developed for low-frequency ME effects in an assembly of fibers and takes into account dipole–dipole interactions between the fibers and fiber discontinuity. Theoretical estimates for the low-frequency MEVC have been compared with the data. These results indicate strong ME coupling in superstructures of the core–shell fibers.
Collapse
|