1
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Gerina M, Sanna Angotzi M, Mameli V, Gajdošová V, Rainer DN, Dopita M, Steinke NJ, Aurélio D, Vejpravová J, Zákutná D. Size dependence of the surface spin disorder and surface anisotropy constant in ferrite nanoparticles. NANOSCALE ADVANCES 2023; 5:4563-4570. [PMID: 37638154 PMCID: PMC10448355 DOI: 10.1039/d3na00266g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 07/14/2023] [Indexed: 08/29/2023]
Abstract
The magnetic properties of nanoscale magnets are greatly influenced by surface anisotropy. So far, its quantification is based on the examination of the blocking temperature shift within a series of nanoparticles of varying sizes. In this scenario, the surface anisotropy is assumed to be a particle size-independent quantity. However, there is no solid experimental proof to support this simplified picture. On the contrary, our work unravels the size-dependent magnetic morphology and surface anisotropy in highly uniform magnetic nanoparticles using small-angle polarized neutron scattering. We observed that the surface anisotropy constant does not depend on the nanoparticle's size in the range of 3-9 nm. Furthermore, our results demonstrate that the surface spins are less prone to polarization with increasing nanoparticle size. Our study thus proves the size dependence of the surface spin disorder and the surface anisotropy constant in fine nanomagnets. These findings open new routes in materials based on a controlled surface spin disorder, which is essential for future applications of nanomagnets in biomedicine and magnonics.
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Affiliation(s)
- Marianna Gerina
- Department of Inorganic Chemistry, Faculty of Science, Charles University Hlavova 2030/8 128 43 Prague 2 Czech Republic
| | - Marco Sanna Angotzi
- Department of Chemical and Geological Sciences, University of Cagliari S.S. 554 bivio per Sestu, 09042 8 Monserrato CA Italy
| | - Valentina Mameli
- Department of Chemical and Geological Sciences, University of Cagliari S.S. 554 bivio per Sestu, 09042 8 Monserrato CA Italy
| | - Veronika Gajdošová
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic 162 06 Prague 6 Czech Republic
| | - Daniel N Rainer
- Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University Hlavova 2030/8 128 43 Prague 2 Czech Republic
| | - Milan Dopita
- Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University Ke Karlovu 5, 121 16 Prague 2 Czech Republic
| | | | - David Aurélio
- Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University Ke Karlovu 5, 121 16 Prague 2 Czech Republic
| | - Jana Vejpravová
- Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University Ke Karlovu 5, 121 16 Prague 2 Czech Republic
| | - Dominika Zákutná
- Department of Inorganic Chemistry, Faculty of Science, Charles University Hlavova 2030/8 128 43 Prague 2 Czech Republic
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2
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Fullerton J, Hierro-Rodriguez A, Donnelly C, Sanz-Hernández D, Skoric L, MacLaren DA, Fernández-Pacheco A. Controlled evolution of three-dimensional magnetic states in strongly coupled cylindrical nanowire pairs. NANOTECHNOLOGY 2023; 34:125301. [PMID: 36595337 DOI: 10.1088/1361-6528/aca9d6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 12/07/2022] [Indexed: 06/17/2023]
Abstract
Cylindrical magnetic nanowires are promising systems for the development of three-dimensional spintronic devices. Here, we simulate the evolution of magnetic states during fabrication of strongly-coupled cylindrical nanowires with varying degrees of overlap. By varying the separation between wires, the relative strength of exchange and magnetostatic coupling can be tuned. Hence, we observe the formation of six fundamental states as a function of both inter-wire separation and wire height. In particular, two complex three-dimensional magnetic states, a 3D Landau Pattern and a Helical domain wall, are observed to emerge for intermediate overlap. These two emergent states show complex spin configurations, including a modulated domain wall with both Néel and Bloch character. The competition of magnetic interactions and the parallel growth scheme we follow (growing both wires at the same time) favours the formation of these anti-parallel metastable states. This works shows how the engineering of strongly coupled 3D nanostructures with competing interactions can be used to create complex spin textures.
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Affiliation(s)
- J Fullerton
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
| | | | - C Donnelly
- Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
| | - D Sanz-Hernández
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, Paris, France
| | - L Skoric
- Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - D A MacLaren
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
| | - A Fernández-Pacheco
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
- Instituto de Nanociencia y Materiales de Aragón, CSIC-Universidad de Zaragoza, Zaragoza, Spain
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3
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Adams MP, Michels A, Kachkachi H. Magnetic neutron scattering from spherical nanoparticles with Néel surface anisotropy: atomistic simulations. J Appl Crystallogr 2022; 55:1488-1499. [PMID: 36570659 PMCID: PMC9721337 DOI: 10.1107/s1600576722008949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 09/06/2022] [Indexed: 11/06/2022] Open
Abstract
A dilute ensemble of randomly oriented non-interacting spherical nanomagnets is considered, and its magnetization structure and ensuing neutron scattering response are investigated by numerically solving the Landau-Lifshitz equation. Taking into account the isotropic exchange interaction, an external magnetic field, a uniaxial magnetic anisotropy for the particle core, and in particular the Néel surface anisotropy, the magnetic small-angle neutron scattering cross section and pair-distance distribution function are calculated from the obtained equilibrium spin structures. The numerical results are compared with the well known analytical expressions for uniformly magnetized particles and provide guidance to the experimentalist. In addition, the effect of a particle-size distribution function is modelled.
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Affiliation(s)
- Michael P. Adams
- Department of Physics and Materials Science, University of Luxembourg, 162A avenue de la Faiencerie, L-1511 Luxembourg, Grand Duchy of Luxembourg
| | - Andreas Michels
- Department of Physics and Materials Science, University of Luxembourg, 162A avenue de la Faiencerie, L-1511 Luxembourg, Grand Duchy of Luxembourg
| | - Hamid Kachkachi
- Laboratoire PROMES CNRS UPR8521, Université de Perpignan via Domitia, Rambla de la Thermodynamique, Tecnosud, F-66100 Perpignan, France
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4
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Adams MP, Michels A, Kachkachi H. Magnetic neutron scattering from spherical nanoparticles with Néel surface anisotropy: analytical treatment. J Appl Crystallogr 2022; 55:1475-1487. [PMID: 36570665 PMCID: PMC9721331 DOI: 10.1107/s1600576722008925] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 09/06/2022] [Indexed: 11/06/2022] Open
Abstract
The magnetization profile and the related magnetic small-angle neutron scattering cross section of a single spherical nanoparticle with Néel surface anisotropy are analytically investigated. A Hamiltonian is employed that comprises the isotropic exchange interaction, an external magnetic field, a uniaxial magnetocrystalline anisotropy in the core of the particle and the Néel anisotropy at the surface. Using a perturbation approach, the determination of the magnetization profile can be reduced to a Helmholtz equation with Neumann boundary condition, whose solution is represented by an infinite series in terms of spherical harmonics and spherical Bessel functions. From the resulting infinite series expansion, the Fourier transform, which is algebraically related to the magnetic small-angle neutron scattering cross section, is analytically calculated. The approximate analytical solution for the spin structure is compared with the numerical solution using the Landau-Lifshitz equation, which accounts for the full nonlinearity of the problem. The signature of the Néel surface anisotropy can be identified in the magnetic neutron scattering observables, but its effect is relatively small, even for large values of the surface anisotropy constant.
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Affiliation(s)
- Michael P. Adams
- Department of Physics and Materials Science, University of Luxembourg, 162A avenue de la Faiencerie, L-1511 Luxembourg, Grand Duchy of Luxembourg
| | - Andreas Michels
- Department of Physics and Materials Science, University of Luxembourg, 162A avenue de la Faiencerie, L-1511 Luxembourg, Grand Duchy of Luxembourg
| | - Hamid Kachkachi
- Laboratoire PROMES CNRS UPR8521, Université de Perpignan via Domitia, Rambla de la Thermodynamique, Tecnosud, F-66100 Perpignan, France
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5
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Samardak AY, Jeon YS, Samardak VY, Kozlov AG, Rogachev KA, Ognev AV, Jeong E, Kim GW, Ko MJ, Samardak AS, Kim YK. Interwire and Intrawire Magnetostatic Interactions in Fe-Au Barcode Nanowires with Alternating Ferromagnetically Strong and Weak Segments. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2203555. [PMID: 36192153 DOI: 10.1002/smll.202203555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 09/07/2022] [Indexed: 06/16/2023]
Abstract
Metallic barcode nanowires (BNWs) composed of repeating heterogeneous segments fabricated by template-assisted electrodeposition can offer extended functionality in magnetic, electrical, mechanical, and biomedical applications. The authors consider such nanostructures as a 3D system of magnetically interacting elements with magnetic behavior strongly affected by complex magnetostatic interactions. This study discusses the influence of geometrical parameters of segments on the character of their interactions and the overall magnetic behavior of the array of BNWs having alternating magnetization, because the Fe and Au segments are made of Fe-Au alloys with high and low magnetizations. By controlling the applied current densities and the elapsed time in the electrodeposition, the dimension of the Fe-Au BNWs can be regulated. This study reveals that the influence of the length of magnetically weak Au segments on the interaction field between nanowires is different for samples with magnetically strong 100 and 200 nm long Fe segments using the first-order reversal curve (FORC) diagram method. With the help of micromagnetic simulations, three types of magnetostatic interactions in the BNW arrays are discovered and analy. This study demonstrates that the dominating type of interaction depends on the geometric parameters of the Fe and Au segments and the interwire and intrawire distances.
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Affiliation(s)
- Aleksei Yu Samardak
- Institute of High Technologies and Advanced Materials, Far Eastern Federal University, Vladivostok, 690922, Russia
| | - Yoo Sang Jeon
- Center for Hydrogen·Fuel Cell Research, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Vadim Yu Samardak
- Institute of High Technologies and Advanced Materials, Far Eastern Federal University, Vladivostok, 690922, Russia
| | - Alexey G Kozlov
- Institute of High Technologies and Advanced Materials, Far Eastern Federal University, Vladivostok, 690922, Russia
| | - Kirill A Rogachev
- Institute of High Technologies and Advanced Materials, Far Eastern Federal University, Vladivostok, 690922, Russia
| | - Alexey V Ognev
- Institute of High Technologies and Advanced Materials, Far Eastern Federal University, Vladivostok, 690922, Russia
| | - Eunjin Jeong
- Department of Materials Science and Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Gyu Won Kim
- Department of Materials Science and Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Min Jun Ko
- Department of Materials Science and Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Alexander S Samardak
- Institute of High Technologies and Advanced Materials, Far Eastern Federal University, Vladivostok, 690922, Russia
| | - Young Keun Kim
- Department of Materials Science and Engineering, Korea University, Seoul, 02841, Republic of Korea
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6
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Abbas MH, Ramazani A, Montazer AH, Almasi Kashi M. Magnetization reversal properties and magnetostatic interactions of disk to rod-shaped FeNi layers separated by ultra-thin Cu layers. NANOTECHNOLOGY 2022; 33:365701. [PMID: 35623331 DOI: 10.1088/1361-6528/ac7404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 05/27/2022] [Indexed: 06/15/2023]
Abstract
From fast magnetic memories with low-power consumption to recording media with high densities, realizing the magnetization reversal and interaction of magnetic layers would allow for manipulating the ultimate properties. Here, we use a pulsed electrochemical deposition technique in porous alumina templates (50 nm in pore diameter) to fabricate arrays of nanowires, consisting of FeNi layers (26-227 nm in thickness) with disk to rod-shaped morphologies separated by ultra-thin (3 nm) Cu layers. By acquiring hysteresis curves and first-order reversal curves (FORCs) of the multilayer nanowire arrays, we comprehensively investigate magnetization reversal properties and magnetostatic interactions of the layers at different field angles (0° ≤θ≤ 90°). These involve the extraction of several parameters, including hysteresis curve coercivity (HcHyst), FORC coercivity (HcFORC), interaction field distribution width (ΔHu), and irreversible fraction of magnetization (IFm) as a function ofθ. We find relatively constant and continuously decreasing trends ofHcHystwhen 0° ≤θ≤ 45°, and 45° < θ≤ 90°, respectively. Meanwhile, angular dependence ofHcFORCandIFmshows continuously increasing and decreasing trends, irrespective of the FeNi layer morphology. Our FORC results indicate the magnetization reversal properties of the FeNi/Cu nanowires are accompanied with vortex domain wall and single vortex modes, especially at high field angles. The rod-shaped layers also induce maximum ΔHuduring the reversal process, owing to enhancements in both magnetizing and demagnetizing-type magnetostatic interactions.
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Affiliation(s)
- Mohammed H Abbas
- Department of Physics, University of Kashan, Kashan 87317-51167, Iran
- Medical Physics Department, Al-Mustaqbal University College, Babylon, Iraq
| | - A Ramazani
- Department of Physics, University of Kashan, Kashan 87317-51167, Iran
- Institute of Nanoscience and Nanotechnology, University of Kashan, Kashan 87317-51167, Iran
| | - A H Montazer
- Institute of Nanoscience and Nanotechnology, University of Kashan, Kashan 87317-51167, Iran
| | - M Almasi Kashi
- Department of Physics, University of Kashan, Kashan 87317-51167, Iran
- Institute of Nanoscience and Nanotechnology, University of Kashan, Kashan 87317-51167, Iran
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7
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Malyeyev A, Titov I, Dewhurst C, Suzuki K, Honecker D, Michels A. Uniaxial polarization analysis of bulk ferromagnets: theory and first experimental results. J Appl Crystallogr 2022; 55:569-585. [PMID: 35719309 PMCID: PMC9172034 DOI: 10.1107/s1600576722003508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 03/28/2022] [Indexed: 11/10/2022] Open
Abstract
On the basis of Brown's static equations of micromagnetics, the uniaxial polarization of the scattered neutron beam of a bulk magnetic material is computed. The approach considers a Hamiltonian that takes into account the isotropic exchange interaction, the antisymmetric Dzyaloshinskii–Moriya interaction, magnetic anisotropy, the dipole–dipole interaction and the effect of an applied magnetic field. In the high-field limit, the solutions for the magnetization Fourier components are used to obtain closed-form results for the spin-polarized small-angle neutron scattering (SANS) cross sections and the ensuing polarization. The theoretical expressions are compared with experimental data on a soft magnetic nanocrystalline alloy. The micromagnetic SANS theory provides a general framework for polarized real-space neutron methods, and it may open up a new avenue for magnetic neutron data analysis on magnetic microstructures.
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8
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Bran C, Saugar E, Fernandez-Roldan JA, Del Real RP, Asenjo A, Aballe L, Foerster M, Fraile Rodríguez A, Palmero EM, Vazquez M, Chubykalo-Fesenko O. Stochastic vs. deterministic magnetic coding in designed cylindrical nanowires for 3D magnetic networks. NANOSCALE 2021; 13:12587-12593. [PMID: 34259293 DOI: 10.1039/d1nr02337c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Advances in cylindrical nanowires for 3D information technologies profit from intrinsic curvature that introduces significant differences with regards to planar systems. A model is proposed to control the stochastic and deterministic coding of remanent 3D complex vortex configurations in designed multilayered (magnetic/non-magnetic) cylindrical nanowires. This concept, introduced by micromagnetic simulations, is experimentally confirmed by magnetic imaging in FeCo/Cu multilayered nanowires. The control over the random/deterministic vortex states configurations is achieved by a suitable geometrical interface tilting of almost non-interacting FeCo segments with respect to the nanowire axis, together with the relative orientation of the perpendicular magnetic field. The proper design of the segments' geometry (e.g. tilting) in cylindrical nanowires opens multiple opportunities for advanced nanotechnologies in 3D magnetic networks.
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Affiliation(s)
- Cristina Bran
- Instituto de Ciencia de Materiales de Madrid, CSIC, Madrid, 28049, Spain.
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9
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Bender P, Leliaert J, Bersweiler M, Honecker D, Michels A. Unraveling Nanostructured Spin Textures in Bulk Magnets. SMALL SCIENCE 2021. [DOI: 10.1002/smsc.202000003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Philipp Bender
- Department of Physics and Materials Science University of Luxembourg 162A Avenue de la Faïencerie L-1511 Luxembourg Grand Duchy of Luxembourg
| | - Jonathan Leliaert
- Department of Solid State Sciences Ghent University Krijgslaan 281/S1 9000 Ghent Belgium
| | - Mathias Bersweiler
- Department of Physics and Materials Science University of Luxembourg 162A Avenue de la Faïencerie L-1511 Luxembourg Grand Duchy of Luxembourg
| | - Dirk Honecker
- Department of Physics and Materials Science University of Luxembourg 162A Avenue de la Faïencerie L-1511 Luxembourg Grand Duchy of Luxembourg
| | - Andreas Michels
- Department of Physics and Materials Science University of Luxembourg 162A Avenue de la Faïencerie L-1511 Luxembourg Grand Duchy of Luxembourg
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10
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Bran C, Fernandez-Roldan JA, P Del Real R, Asenjo A, Chen YS, Zhang J, Zhang X, Fraile Rodríguez A, Foerster M, Aballe L, Chubykalo-Fesenko O, Vazquez M. Unveiling the Origin of Multidomain Structures in Compositionally Modulated Cylindrical Magnetic Nanowires. ACS NANO 2020; 14:12819-12827. [PMID: 32970409 DOI: 10.1021/acsnano.0c03579] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
CoNi/Ni multisegmented cylindrical nanowires were synthesized via an electrochemical route. The wires are 140 nm in diameter, with 1000 nm long Ni segments and CoNi segments between 600 and 1400 nm in length. The magnetic configuration was imaged by XMCD-PEEM in the demagnetized state and at remanence after magnetizing axially and perpendicularly. Ni segments, with cubic crystal symmetry, show an axial magnetic configuration with a small curling component at the surface. In turn, CoNi segments, with hexagonal crystal symmetry and a strong magnetocrystalline anisotropy perpendicular to the nanowires, show a single vortex state in the shorter segments and multivortex or multitransverse magnetic configurations in medium and long segments, respectively. A detailed study by micromagnetic simulations reveals that the magnetic configuration is determined mainly by the coupling between soft Ni and harder CoNi segments. For short CoNi segments, Ni segments are magnetostatically coupled and the chirality of the single vortex formed in CoNi remains the same as that of the curling in neighboring Ni segments. For longer CoNi segments, the remanent state is either the multivortex or multitransverse state depending on whether the previously applied field was parallel or perpendicular to the magnetocrystalline axis. The results point out the relevance of the cylindrical geometry to promote the occurrence of complex magneto-chiral effects and provide key information for the design of cylindrical magnetic nanowires for multiple applications.
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Affiliation(s)
- Cristina Bran
- Instituto de Ciencia de Materiales de Madrid, CSIC, Madrid 28049, Spain
| | - Jose Angel Fernandez-Roldan
- Instituto de Ciencia de Materiales de Madrid, CSIC, Madrid 28049, Spain
- Department of Physics, University of Oviedo, Oviedo 33007, Spain
| | - Rafael P Del Real
- Instituto de Ciencia de Materiales de Madrid, CSIC, Madrid 28049, Spain
| | - Agustina Asenjo
- Instituto de Ciencia de Materiales de Madrid, CSIC, Madrid 28049, Spain
| | - Yu-Shen Chen
- Instituto de Ciencia de Materiales de Madrid, CSIC, Madrid 28049, Spain
- Department of Chemical Engineering and Materials Science, Yuan-Ze University, Chung-Li 32003, Taiwan
| | - Junli Zhang
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia
| | - Xixiang Zhang
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia
| | - Arantxa Fraile Rodríguez
- Departament de Física de la Matèria Condensada, Universitat de Barcelona, Barcelona 08028, Spain
- Institut de Nanociencia i Nanotecnologia (IN2UB), Universitat de Barcelona, Barcelona 08028, Spain
| | | | - Lucia Aballe
- ALBA Synchrotron Light Facility, CELLS, Barcelona 08290, Spain
| | | | - Manuel Vazquez
- Instituto de Ciencia de Materiales de Madrid, CSIC, Madrid 28049, Spain
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11
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Vivas LG, Yanes R, Berkov D, Erokhin S, Bersweiler M, Honecker D, Bender P, Michels A. Toward Understanding Complex Spin Textures in Nanoparticles by Magnetic Neutron Scattering. PHYSICAL REVIEW LETTERS 2020; 125:117201. [PMID: 32976012 DOI: 10.1103/physrevlett.125.117201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 07/03/2020] [Accepted: 08/12/2020] [Indexed: 05/27/2023]
Abstract
In the quest to image the three-dimensional magnetization structure we show that the technique of magnetic small-angle neutron scattering (SANS) is highly sensitive to the details of the internal spin structure of nanoparticles. By combining SANS with numerical micromagnetic computations we study the transition from single-domain to multidomain behavior in nanoparticles and its implications for the ensuing magnetic SANS cross section. Above the critical single-domain size we find that the cross section and the related correlation function cannot be described anymore with the uniform particle model, resulting, e.g., in deviations from the well-known Guinier law. In the simulations we identify a clear signature for the occurrence of a vortexlike spin structure at remanence. The micromagnetic approach to magnetic SANS bears great potential for future investigations, since it provides fundamental insights into the mesoscale magnetization profile of nanoparticles.
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Affiliation(s)
- Laura G Vivas
- Department of Physics and Materials Science, University of Luxembourg, 162A avenue de la Faïencerie, L-1511 Luxembourg, Grand Duchy of Luxembourg
| | - Rocio Yanes
- Department of Applied Physics, University of Salamanca, Salamanca 37008, Spain
| | - Dmitry Berkov
- General Numerics Research Lab, Moritz-von-Rohr-Straße 1A, D-07745 Jena, Germany
| | - Sergey Erokhin
- General Numerics Research Lab, Moritz-von-Rohr-Straße 1A, D-07745 Jena, Germany
| | - Mathias Bersweiler
- Department of Physics and Materials Science, University of Luxembourg, 162A avenue de la Faïencerie, L-1511 Luxembourg, Grand Duchy of Luxembourg
| | - Dirk Honecker
- Department of Physics and Materials Science, University of Luxembourg, 162A avenue de la Faïencerie, L-1511 Luxembourg, Grand Duchy of Luxembourg
| | - Philipp Bender
- Department of Physics and Materials Science, University of Luxembourg, 162A avenue de la Faïencerie, L-1511 Luxembourg, Grand Duchy of Luxembourg
| | - Andreas Michels
- Department of Physics and Materials Science, University of Luxembourg, 162A avenue de la Faïencerie, L-1511 Luxembourg, Grand Duchy of Luxembourg
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12
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Orientation Growth and Magnetic Properties of Electrochemical Deposited Nickel Nanowire Arrays. Catalysts 2019. [DOI: 10.3390/catal9020152] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Highly ordered ferromagnetic metal nanowire arrays with preferred growth direction show potential applications in electronic and spintronic devices. In this work, by employing a porous anodic aluminum oxide template-assisted electrodeposition method, we successfully prepared Ni nanowire arrays. Importantly, the growth direction of Ni nanowire arrays can be controlled by varying the current densities. The crystalline and growth orientation of Ni nanowire arrays show effects on magnetic properties. Single-crystallinity Ni nanowires with [110] orientation show the best magnetic properties, including coercivity and squareness, along the parallel direction of the nanowire axis. The current preparation strategy can be used to obtain other nanowire arrays (such as metal, alloy, and semiconductor) with controlled growth direction in confined space, and is therefore of broad interest for different applications.
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13
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Stadler BJH, Reddy M, Basantkumar R, McGary P, Estrine E, Huang X, Sung SY, Tan L, Zou J, Maqableh M, Shore D, Gage T, Um J, Hein M, Sharma A. Galfenol Thin Films and Nanowires. SENSORS 2018; 18:s18082643. [PMID: 30103550 PMCID: PMC6111928 DOI: 10.3390/s18082643] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 07/25/2018] [Accepted: 07/26/2018] [Indexed: 02/05/2023]
Abstract
Galfenol (Fe1−xGax, 10 < x < 40) may be the only smart material that can be made by electrochemical deposition which enables thick film and nanowire structures. This article reviews the deposition, characterization, and applications of Galfenol thin films and nanowires. Galfenol films have been made by sputter deposition as well as by electrochemical deposition, which can be difficult due to the insolubility of gallium. However, a stable process has been developed, using citrate complexing, a rotating disk electrode, Cu seed layers, and pulsed deposition. Galfenol thin films and nanowires have been characterized for crystal structures and magnetostriction both by our group and by collaborators. Films and nanowires have been shown to be largely polycrystalline, with magnetostrictions that are on the same order of magnitude as textured bulk Galfenol. Electrodeposited Galfenol films were made with epitaxial texture on GaAs. Galfenol nanowires have been made by electrodeposition into anodic aluminum oxide templates using similar parameters defined for films. Segmented nanowires of Galfenol/Cu have been made to provide engineered magnetic properties. Applications of Galfenol and other magnetic nanowires include microfluidic sensors, magnetic separation, cellular radio-frequency identification (RFID) tags, magnetic resonance imaging (MRI) contrast, and hyperthermia.
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Affiliation(s)
- Bethanie J H Stadler
- Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
- Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Madhukar Reddy
- Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Rajneeta Basantkumar
- Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Patrick McGary
- Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Eliot Estrine
- Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Xiaobo Huang
- Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Sang Yeob Sung
- Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Liwen Tan
- Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Jia Zou
- Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Mazin Maqableh
- Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Daniel Shore
- Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Thomas Gage
- Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Joseph Um
- Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Matthew Hein
- Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Anirudh Sharma
- Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
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14
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Bran C, Berganza E, Fernandez-Roldan JA, Palmero EM, Meier J, Calle E, Jaafar M, Foerster M, Aballe L, Fraile Rodriguez A, P Del Real R, Asenjo A, Chubykalo-Fesenko O, Vazquez M. Magnetization Ratchet in Cylindrical Nanowires. ACS NANO 2018; 12:5932-5939. [PMID: 29812903 DOI: 10.1021/acsnano.8b02153] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The unidirectional motion of information carriers such as domain walls in magnetic nanostrips is a key feature for many future spintronic applications based on shift registers. This magnetic ratchet effect has so far been achieved in a limited number of complex nanomagnetic structures, for example, by lithographically engineered pinning sites. Here we report on a simple remagnetization ratchet originated in the asymmetric potential from the designed increasing lengths of magnetostatically coupled ferromagnetic segments in FeCo/Cu cylindrical nanowires. The magnetization reversal in neighboring segments propagates sequentially in steps starting from the shorter segments, irrespective of the applied field direction. This natural and efficient ratchet offers alternatives for the design of three-dimensional advanced storage and logic devices.
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Affiliation(s)
- Cristina Bran
- Institute of Materials Science of Madrid, CSIC , 28049 Madrid , Spain
| | - Eider Berganza
- Institute of Materials Science of Madrid, CSIC , 28049 Madrid , Spain
| | | | - Ester M Palmero
- Institute of Materials Science of Madrid, CSIC , 28049 Madrid , Spain
| | - Jessica Meier
- Institute of Materials Science of Madrid, CSIC , 28049 Madrid , Spain
| | - Esther Calle
- Institute of Materials Science of Madrid, CSIC , 28049 Madrid , Spain
| | - Miriam Jaafar
- Institute of Materials Science of Madrid, CSIC , 28049 Madrid , Spain
| | - Michael Foerster
- ALBA Synchrotron Light Facility, CELLS , 08290 Barcelona , Spain
| | - Lucia Aballe
- ALBA Synchrotron Light Facility, CELLS , 08290 Barcelona , Spain
| | | | - Rafael P Del Real
- Institute of Materials Science of Madrid, CSIC , 28049 Madrid , Spain
| | - Agustina Asenjo
- Institute of Materials Science of Madrid, CSIC , 28049 Madrid , Spain
| | | | - Manuel Vazquez
- Institute of Materials Science of Madrid, CSIC , 28049 Madrid , Spain
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15
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Zhao S, Han F, Li J, Meng X, Huang W, Cao D, Zhang G, Sun R, Wong CP. Advancements in Copper Nanowires: Synthesis, Purification, Assemblies, Surface Modification, and Applications. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:e1800047. [PMID: 29707894 DOI: 10.1002/smll.201800047] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 02/08/2018] [Indexed: 06/08/2023]
Abstract
Copper nanowires (CuNWs) are attracting a myriad of attention due to their preponderant electric conductivity, optoelectronic and mechanical properties, high electrocatalytic efficiency, and large abundance. Recently, great endeavors are undertaken to develop controllable and facile approaches to synthesize CuNWs with high dispersibility, oxidation resistance, and zero defects for future large-scale nano-enabled materials. Herein, this work provides a comprehensive review of current remarkable advancements in CuNWs. The Review starts with a thorough overview of recently developed synthetic strategies and growth mechanisms to achieve single-crystalline CuNWs and fivefold twinned CuNWs by the reduction of Cu(I) and Cu(II) ions, respectively. Following is a discussion of CuNW purification and multidimensional assemblies comprising films, aerogels, and arrays. Next, several effective approaches to protect CuNWs from oxidation are highlighted. The emerging applications of CuNWs in diverse fields are then focused on, with particular emphasis on optoelectronics, energy storage/conversion, catalysis, wearable electronics, and thermal management, followed by a brief comment on the current challenges and future research directions. The central theme of the Review is to provide an intimate correlation among the synthesis, structure, properties, and applications of CuNWs.
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Affiliation(s)
- Songfang Zhao
- School of Material Science and Engineering, University of Jinan, Jinan, 250022, Shandong, China
| | - Fei Han
- Guangdong Provincial Key Laboratory of Materials for High Density Electronic Packaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
- Department of Nano Science and Technology Institute, University of Science and Technology of China, Suzhou, 215123, China
| | - Jinhui Li
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
| | - Xiangying Meng
- School of Material Science and Engineering, University of Jinan, Jinan, 250022, Shandong, China
| | - Wangping Huang
- Guangdong Provincial Key Laboratory of Materials for High Density Electronic Packaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
- Department of Nano Science and Technology Institute, University of Science and Technology of China, Suzhou, 215123, China
| | - Duxia Cao
- School of Material Science and Engineering, University of Jinan, Jinan, 250022, Shandong, China
| | - Guoping Zhang
- Guangdong Provincial Key Laboratory of Materials for High Density Electronic Packaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Rong Sun
- Guangdong Provincial Key Laboratory of Materials for High Density Electronic Packaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Ching-Ping Wong
- School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, GA, 30332, USA
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16
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