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Yang CK, Jiao L. Superconducting Two-Dimensional FeSe Grown on the Fe-Enriched Interface. ACS NANO 2024; 18:12276-12283. [PMID: 38700494 DOI: 10.1021/acsnano.4c00984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2024]
Abstract
Two-dimensional (2D) tetragonal FeSe has sparked extensive research interest owing to its tunable superconductivity, providing valuable insights into the design of high-temperature superconductors. Currently, the intricate Fe-Se phase diagram poses a challenge to the controlled synthesis of superconducting 2D FeSe in a pure tetragonal phase. Here, we exploit the ion-exchange property of fluorophlogopite mica to devise a straightforward approach for the phase-controlled synthesis of tetragonal FeSe on an Fe-enriched mica surface within a molten salt environment. This method successfully produces highly crystalline FeSe in a pure tetragonal phase with adjustable thickness. We investigated the surface composition of the postgrowth mica substrate using various microscopic and spectroscopic characterizations to highlight the importance of the Fe-enriched growth interface in the phase-selective synthesis of 2D tetragonal FeSe. The obtained 2D FeSe exhibited 2D superconductivity, comparable to that of FeSe mechanically exfoliated from bulk crystals, confirming the high quality of our samples. Beyond tetragonal FeSe, 2D antiferromagnetic FeTe and superconducting FeSxSeyTe1-x-y have been phase-selectively synthesized via this approach. Our study elucidates the significance of the growth interface on the phase-selective synthesis of 2D materials and presents potential opportunities for the phase-controlled synthesis of 2D multiphase materials via the rational design of the growth interface.
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Affiliation(s)
- Chen-Kai Yang
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Liying Jiao
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084, China
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2
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Arshad M, Sorba L, Rudolf P, Cepek C. Growth and Characterization of Carbon Nanofibers Grown on Vertically Aligned InAs Nanowires via Chemical Vapour Deposition. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:3083. [PMID: 38132981 PMCID: PMC10746074 DOI: 10.3390/nano13243083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 11/24/2023] [Accepted: 11/27/2023] [Indexed: 12/23/2023]
Abstract
The integration of carbon nanostructures with semiconductor nanowires holds significant potential for energy-efficient integrated circuits. However, achieving precise control over the positioning and stability of these interconnections poses a major challenge. This study presents a method for the controlled growth of carbon nanofibers (CNFs) on vertically aligned indium arsenide (InAs) nanowires. The CNF/InAs hybrid structures, synthesized using chemical vapor deposition (CVD), were successfully produced without compromising the morphology of the pristine nanowires. Under optimized conditions, preferential growth of the carbon nanofibers in the direction perpendicular to the InAs nanowires was observed. Moreover, when the CVD process employed iron as a catalyst, an increased growth rate was achieved. With and without the presence of iron, carbon nanofibers nucleate preferentially on the top of the InAs nanowires, indicating a tip growth mechanism presumably catalysed by a gold-indium alloy that selectively forms in that region. These results represent a compelling example of controlled interconnections between adjacent InAs nanowires formed by carbon fibers.
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Affiliation(s)
- Muhammad Arshad
- Istituto Officina dei Materiali—CNR, Laboratorio TASC Area Science Park—Basovizza, Edificio MM, Strada Statale 14, Km.163.5, I-34149 Trieste, Italy;
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, NL-9747AG Groningen, The Netherlands;
- Nanosciences and Technology Department, National Center for Physics, Quaid-i-Azam University Campus, Islamabad 2141, Pakistan
| | - Lucia Sorba
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza S. Silvestro 12, I-56127 Pisa, Italy;
| | - Petra Rudolf
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, NL-9747AG Groningen, The Netherlands;
| | - Cinzia Cepek
- Istituto Officina dei Materiali—CNR, Laboratorio TASC Area Science Park—Basovizza, Edificio MM, Strada Statale 14, Km.163.5, I-34149 Trieste, Italy;
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3
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Azam M, Manasa M, Zajarniuk T, Diduszko R, Cetner T, Morawski A, Więckowski J, Wiśniewski A, Singh SJ. High-Pressure Synthesis and the Enhancement of the Superconducting Properties of FeSe 0.5Te 0.5. MATERIALS (BASEL, SWITZERLAND) 2023; 16:5358. [PMID: 37570064 PMCID: PMC10419941 DOI: 10.3390/ma16155358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 07/27/2023] [Accepted: 07/28/2023] [Indexed: 08/13/2023]
Abstract
A series of FeSe0.5Te0.5 bulk samples have been prepared using the high gas pressure and high-temperature synthesis (HP-HTS) method to optimize the growth conditions for the first time and investigated for their superconducting properties using structural, microstructure, transport, and magnetic measurements to reach the final conclusions. Ex situ and in situ processes are used to prepare bulk samples under a range of growth pressures using Ta-tube and without Ta-tube. The parent compound synthesized by convenient synthesis method at ambient pressure (CSP) exhibits a superconducting transition temperature of 14.8 K. Our data demonstrate that the prepared FeSe0.5Te0.5 sealed in a Ta-tube is of better quality than the samples without a Ta-tube, and the optimum growth conditions (500 MPa, 600 °C for 1 h) are favorable for the development of the tetragonal FeSe0.5Te0.5 phase. The optimum bulk FeSe0.5Te0.5 depicts a higher transition temperature of 17.3 K and a high critical current density of the order of >104 A/cm2 at 0 T, which is improved over the entire magnetic field range and almost twice higher than the parent compound prepared using CSP. Our studies confirm that the high-pressure synthesis method is a highly efficient way to improve the superconducting transition, grain connectivity, sample density, and pinning properties of a superconductor.
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Affiliation(s)
- Mohammad Azam
- Institute of High Pressure Physics (IHPP), Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warsaw, Poland
| | - Manasa Manasa
- Institute of High Pressure Physics (IHPP), Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warsaw, Poland
| | - Tatiana Zajarniuk
- Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland
| | - Ryszard Diduszko
- Łukasiewicz Research Network Institute of Microelectronics and Photonics, Aleja Lotników 32/46, 02-668 Warsaw, Poland
| | - Tomasz Cetner
- Institute of High Pressure Physics (IHPP), Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warsaw, Poland
| | - Andrzej Morawski
- Institute of High Pressure Physics (IHPP), Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warsaw, Poland
| | - Jarosław Więckowski
- Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland
| | - Andrzej Wiśniewski
- Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland
| | - Shiv J. Singh
- Institute of High Pressure Physics (IHPP), Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warsaw, Poland
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4
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Hou Q, Sun L, Sun Y, Shi Z. Review of Single Crystal Synthesis of 11 Iron-Based Superconductors. MATERIALS (BASEL, SWITZERLAND) 2023; 16:4895. [PMID: 37512171 PMCID: PMC10381650 DOI: 10.3390/ma16144895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 06/27/2023] [Accepted: 07/05/2023] [Indexed: 07/30/2023]
Abstract
The 11 system in the iron-based superconducting family has become one of the most extensively studied materials in the research of high-temperature superconductivity, due to their simple structure and rich physical properties. Many exotic properties, such as multiband electronic structure, electronic nematicity, topology and antiferromagnetic order, provide strong support for the theory of high-temperature superconductivity, and have been at the forefront of condensed matter physics in the past decade. One noteworthy aspect is that a high upper critical magnetic field, large critical current density and lower toxicity give the 11 system good application prospects. However, the research on 11 iron-based superconductors faces numerous obstacles, mainly stemming from the challenges associated with producing high-quality single crystals. Since the discovery of FeSe superconductivity in 2008, researchers have made significant progress in crystal growth, overcoming the hurdles that initially impeded their studies. Consequently, they have successfully established the complete phase diagrams of 11 iron-based superconductors, including FeSe1-xTex, FeSe1-xSx and FeTe1-xSx. In this paper, we aim to provide a comprehensive summary of the preparation methods employed for 11 iron-based single crystals over the past decade. Specifically, we will focus on hydrothermal, chemical vapor transport (CVT), self-flux and annealing methods. Additionally, we will discuss the quality, size, and superconductivity properties exhibited by single crystals obtained through different preparation methods. By exploring these aspects, we can gain a better understanding of the advantages and limitations associated with each technique. High-quality single crystals serve as invaluable tools for advancing both the theoretical understanding and practical utilization of high-temperature superconductivity.
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Affiliation(s)
- Qiang Hou
- School of Physics, Southeast University, Nanjing 211189, China
| | - Longfei Sun
- School of Physics, Southeast University, Nanjing 211189, China
| | - Yue Sun
- School of Physics, Southeast University, Nanjing 211189, China
| | - Zhixiang Shi
- School of Physics, Southeast University, Nanjing 211189, China
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5
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Manasa M, Azam M, Zajarniuk T, Diduszko R, Cetner T, Morawski A, Wiśniewski A, Singh SJ. Cometal Addition Effect on Superconducting Properties and Granular Behaviours of Polycrystalline FeSe 0.5Te 0.5. MATERIALS (BASEL, SWITZERLAND) 2023; 16:2892. [PMID: 37049186 PMCID: PMC10095744 DOI: 10.3390/ma16072892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 04/01/2023] [Accepted: 04/03/2023] [Indexed: 06/19/2023]
Abstract
The enhanced performance of superconducting FeSe0.5Te0.5 materials with added micro-sized Pb and Sn particles is presented. A series of Pb- and Sn-added FeSe0.5Te0.5 (FeSe0.5Te0.5 + xPb + ySn; x = y = 0-0.1) bulks are fabricated by the solid-state reaction method and characterized through various measurements. A very small amount of Sn and Pb additions (x = y ≤ 0.02) enhance the transition temperature (Tconset) of pure FeSe0.5Te0.5 by ~1 K, sharpening the superconducting transition and improving the metallic nature in the normal state, whereas larger metal additions (x = y ≥ 0.03) reduce Tconset by broadening the superconducting transition. Microstructural analysis and transport studies suggest that at x = y > 0.02, Pb and Sn additions enhance the impurity phases, reduce the coupling between grains, and suppress the superconducting percolation, leading to a broad transition. FeSe0.5Te0.5 samples with 2 wt% of cometal additions show the best performance with their critical current density, Jc, and the pinning force, Fp, which might be attributable to providing effective flux pinning centres. Our study shows that the inclusion of a relatively small amount of Pb and Sn (x = y ≤ 0.02) works effectively for the enhancement of superconducting properties with an improvement of intergrain connections as well as better phase uniformity.
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Affiliation(s)
- Manasa Manasa
- Institute of High Pressure Physics (IHPP), Polish Academy of Sciences, Sokolowska 29/37, 01-142 Warsaw, Poland
| | - Mohammad Azam
- Institute of High Pressure Physics (IHPP), Polish Academy of Sciences, Sokolowska 29/37, 01-142 Warsaw, Poland
| | - Tatiana Zajarniuk
- Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland
| | - Ryszard Diduszko
- Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland
- Institute of Microelectronics and Photonics, Wólczyńska 133, 01-919 Warsaw, Poland
| | - Tomasz Cetner
- Institute of High Pressure Physics (IHPP), Polish Academy of Sciences, Sokolowska 29/37, 01-142 Warsaw, Poland
| | - Andrzej Morawski
- Institute of High Pressure Physics (IHPP), Polish Academy of Sciences, Sokolowska 29/37, 01-142 Warsaw, Poland
| | - Andrzej Wiśniewski
- Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland
| | - Shiv J. Singh
- Institute of High Pressure Physics (IHPP), Polish Academy of Sciences, Sokolowska 29/37, 01-142 Warsaw, Poland
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6
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Wang A, Milosavljevic A, Abeykoon AMM, Ivanovski V, Du Q, Baum A, Stavitski E, Liu Y, Lazarevic N, Attenkofer K, Hackl R, Popovic Z, Petrovic C. Suppression of Superconductivity and Nematic Order in Fe 1-ySe 1-xS x (0 ≤ x ≤ 1; y ≤ 0.1) Crystals by Anion Height Disorder. Inorg Chem 2022; 61:11036-11045. [PMID: 35830279 DOI: 10.1021/acs.inorgchem.2c00568] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Connections between crystal chemistry and critical temperature Tc have been in the focus of superconductivity, one of the most widely studied phenomena in physics, chemistry, and materials science alike. In most Fe-based superconductors, materials chemistry and physics conspire so that Tc correlates with the average anion height above the Fe plane, i.e., with the geometry of the FeAs4 or FeCh4 (Ch = Te, Se, or S) tetrahedron. By synthesizing Fe1-ySe1-xSx (0 ≤ x ≤ 1; y ≤ 0.1), we find that in alloyed crystals Tc is not correlated with the anion height like it is for most other Fe superconductors. Instead, changes in Tc(x) and tetragonal-to-orthorhombic (nematic) transition Ts(x) upon cooling are correlated with disorder in Fe vibrations in the direction orthogonal to Fe planes, along the crystallographic c-axis. The disorder stems from the random nature of S substitution, causing deformed Fe(Se,S)4 tetrahedra with different Fe-Se and Fe-S bond distances. Our results provide evidence of Tc and Ts suppression by disorder in anion height. The connection to local crystal chemistry may be exploited in computational prediction of new superconducting materials with FeSe/S building blocks.
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Affiliation(s)
- Aifeng Wang
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Ana Milosavljevic
- Center for Solid State Physics and New Materials, Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia
| | - A M Milinda Abeykoon
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Valentin Ivanovski
- Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade 11001, Serbia
| | - Qianheng Du
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States.,Materials Science and Chemical Engineering Department, Stony Brook University, Stony Brook, New York 11790, United States
| | - Andreas Baum
- Walther Meissner Institut, Bayerische Akademie der Wissenschaften, 85748 Garching, Germany.,Fakultät für Physik E23, Technische Universität München, 85748 Garching, Germany
| | - Eli Stavitski
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Yu Liu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Nenad Lazarevic
- Center for Solid State Physics and New Materials, Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia
| | - Klaus Attenkofer
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Rudi Hackl
- Walther Meissner Institut, Bayerische Akademie der Wissenschaften, 85748 Garching, Germany.,Fakultät für Physik E23, Technische Universität München, 85748 Garching, Germany
| | - Zoran Popovic
- Center for Solid State Physics and New Materials, Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia.,Serbian Academy of Sciences and Arts, Kneza Mihaila 35, Belgrade 11000, Serbia
| | - Cedomir Petrovic
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States.,Materials Science and Chemical Engineering Department, Stony Brook University, Stony Brook, New York 11790, United States
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7
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Lin Z, Tu S, Xu J, Shi Y, Zhu B, Dong C, Yuan J, Dong X, Chen Q, Li Y, Jin K, Zhao Z. Phase diagrams on composition-spread Fe Te1−Se films. Sci Bull (Beijing) 2022; 67:1443-1449. [DOI: 10.1016/j.scib.2022.06.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/08/2022] [Accepted: 06/13/2022] [Indexed: 10/18/2022]
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8
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Azadar Hussain R, Hamza Safeer S. Low temperature synthesis of iron selenide by thermolysis of organometallic precursor for photodegradation under direct sunlight. RESULTS IN CHEMISTRY 2022. [DOI: 10.1016/j.rechem.2022.100556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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9
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Zhang L, Wei Z, Yao S, Gao Y, Jin X, Chen G, Shen Z, Du F. Polymorph Engineering for Boosted Volumetric Na-Ion and Li-Ion Storage. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2100210. [PMID: 33829567 DOI: 10.1002/adma.202100210] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 02/16/2021] [Indexed: 05/26/2023]
Abstract
To meet the ever-growing demand for advanced rechargeable batteries with light weight and compact size, much effort has been devoted to improving the volumetric capacity of electrodes. Herein, an effective strategy of polymorph engineering is proposed to boost the volumetric capacity of FeSe. Owing to the inherent metallic electronic conductivity of tetragonal-FeSe, a conductive additive-free electrode (hereafter denoted as CA-free) can be assembled with an enhanced sodium storage volumetric capacity of 1011 mAh cm-3 , significantly higher than semiconducting hexagonal-FeSe. Impressively, the CA-free electrode can achieve an extremely high active material utilization of 96.7 wt% and high initial Coulombic efficiency of 96%, superior to most of the anodes for Na-ion storage. Moreover, the design methodology is branched out using tetragonal FeSe as the cathode for Li-ion batteries. The CA-free tetragonal-FeSe electrode can achieve a high volumetric energy density of 1373 Wh L-1 and power density of 7200 W L-1 , outperforming most metal chalcogenides. Reversible conversion reactions are revealed by in situ XRD for both sodium and lithium systems. The proposed design strategy provides new insight and inspiration to aid in the ongoing quest for better electrode materials.
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Affiliation(s)
- Lu Zhang
- Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun, 130012, China
| | - Zhixuan Wei
- Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun, 130012, China
| | - Shiyu Yao
- Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun, 130012, China
| | - Yu Gao
- Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun, 130012, China
| | - Xu Jin
- Research Institute of Petroleum Exploration and Development, PetroChina, Beijing, 100083, China
| | - Gang Chen
- Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun, 130012, China
| | - Zexiang Shen
- Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun, 130012, China
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637616, Singapore
| | - Fei Du
- Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun, 130012, China
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10
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Mamedov FM, Babanly DM, Amiraslanov IR, Tagiev DB, Babanly MB. Physicochemical Analysis of the FeSe–Ga2Se3–In2Se3 System. RUSS J INORG CHEM+ 2020. [DOI: 10.1134/s0036023620110121] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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11
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Koblischka MR, Slimani Y, Koblischka-Veneva A, Karwoth T, Zeng X, Hannachi E, Murakami M. Excess Conductivity Analysis of Polycrystalline FeSe Samples with the Addition of Ag. MATERIALS 2020; 13:ma13215018. [PMID: 33172199 PMCID: PMC7664390 DOI: 10.3390/ma13215018] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 10/31/2020] [Accepted: 11/03/2020] [Indexed: 11/20/2022]
Abstract
Bulk FeSe superconductors of the iron-based (IBS) “11” family containing various additions of silver were thoroughly investigated concerning the microstructure using optical microscopy and electron microscopy (TEM and SEM). The measurements of electrical resistivity were performed through the four-point technique in the temperature interval T= 2–150 K. The Aslamazov–Larkin model was employed to analyze the fluctuation-induced conductivity (FIC) in all acquired measurements. In all studied products, we found that the FIC curves consist of five different regimes of fluctuation, viz. critical region (CR), three-dimensional (3D), two-dimensional (2D), one-dimensional (1D), and shortwave fluctuation (SWF) regimes. The critical current density (Jc), the lower and upper critical magnetic fields (Bc1 and Bc2), the coherence length along the c-axis at zero-temperature (ξc(0)), and further parameters were assessed with regards to the silver amount within the products. The analyses discloses a diminution in the resistivity and a great reduction in ξc(0) with Ag addition. The optimal silver doping amount is achieved for 7 wt.%, which yields the best superconducting transition and the greatest Jc value.
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Affiliation(s)
- Michael Rudolf Koblischka
- Experimental Physics, Saarland University, P.O. Box 151150, D-66044 Saarbrücken, Germany; (A.K.-V.); (T.K.); (X.Z.)
- SIT Research Laboratories, Shibaura Institute of Technology, Tokyo 135-8548, Japan;
- Correspondence: or
| | - Yassine Slimani
- Department of Biophysics, Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia;
| | - Anjela Koblischka-Veneva
- Experimental Physics, Saarland University, P.O. Box 151150, D-66044 Saarbrücken, Germany; (A.K.-V.); (T.K.); (X.Z.)
- SIT Research Laboratories, Shibaura Institute of Technology, Tokyo 135-8548, Japan;
| | - Thomas Karwoth
- Experimental Physics, Saarland University, P.O. Box 151150, D-66044 Saarbrücken, Germany; (A.K.-V.); (T.K.); (X.Z.)
| | - XianLin Zeng
- Experimental Physics, Saarland University, P.O. Box 151150, D-66044 Saarbrücken, Germany; (A.K.-V.); (T.K.); (X.Z.)
| | - Essia Hannachi
- Laboratory of Physics of Materials—Structures and Properties, Department of Physics, Faculty of Sciences of Bizerte, University of Carthage, Zarzouna 7021, Tunisia;
| | - Masato Murakami
- SIT Research Laboratories, Shibaura Institute of Technology, Tokyo 135-8548, Japan;
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12
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Harris SB, Camata RP. X-ray diffraction data and analysis to support phase identification in FeSe and Fe 7Se 8 epitaxial thin films. Data Brief 2019; 27:104778. [PMID: 31763420 PMCID: PMC6864172 DOI: 10.1016/j.dib.2019.104778] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 10/30/2019] [Accepted: 10/31/2019] [Indexed: 10/31/2022] Open
Abstract
X-ray diffraction (XRD) data and analysis for epitaxial iron selenide thin films grown by pulsed laser deposition (PLD) are presented to support the conclusions in the related research article "Double epitaxy of tetragonal and hexagonal phases in the FeSe system" [1]. The films contain β-FeSe and Fe7Se8 phases in a double epitaxy configuration with the β-FeSe phase (001) oriented on the (001) MgO growth substrate. Fe7Se8 simultaneously takes on two different epitaxial orientations in certain growth conditions, exhibiting both (101)- and (001)- orientations. Each of these orientations are verified with the presented XRD data. Additionally, XRD data used to determine the PLD target composition as well as mosaic structure of the β-FeSe phase are shown.
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Affiliation(s)
- Sumner B Harris
- Department of Physics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Renato P Camata
- Department of Physics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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13
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Rasche B, Yang M, Nikonow L, Cooper JFK, Murray CA, Day SJ, Kleiner K, Clarke SJ, Compton RG. In-situ Electrochemical X-ray Diffraction: A Rigorous Method to Navigate within Phase Diagrams Reveals β-Fe 1+x Se as Superconductor for All x. Angew Chem Int Ed Engl 2019; 58:15401-15406. [PMID: 31433102 DOI: 10.1002/anie.201907426] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 08/09/2019] [Indexed: 11/11/2022]
Abstract
We report the precise postsynthetic control of the composition of β-Fe1+x Se by electrochemistry with simultaneous tracking of the associated structural changes via in situ synchrotron X-ray diffraction. We access the full phase width of 0.01<x<0.04 and identify the superconducting state below 8 K, which in contrast to earlier reports is independent of the composition. However, in a second set of in situ X-ray diffraction experiments, we demonstrate that β-Fe1+x Se forms a new phase in the presence of oxygen above a 100 °C which has the same anti-PbO type structure but is not superconducting down to 1.8 K. The latter process can be reversed electrochemically to reinstate the superconducting state. These observations exploit the exquisite control afforded by electrochemistry in contrast with classical approaches of chemical synthesis.
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Affiliation(s)
- Bertold Rasche
- Department of Chemistry, University of Oxford, Oxford, OX1 3QZ, UK
| | - Minjun Yang
- Department of Chemistry, University of Oxford, Oxford, OX1 3QZ, UK
| | - Lothar Nikonow
- Department of Chemistry, University of Oxford, Oxford, OX1 3QZ, UK
| | - Joshaniel F K Cooper
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Harwell Campus, Didcot, OX11 0QX, UK
| | | | - Sarah J Day
- Diamond Light Source, Harwell Campus, Didcot, OX11 0QX, UK
| | - Karin Kleiner
- Diamond Light Source, Harwell Campus, Didcot, OX11 0QX, UK
| | - Simon J Clarke
- Department of Chemistry, University of Oxford, Oxford, OX1 3QZ, UK
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14
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Rasche B, Yang M, Nikonow L, Cooper JFK, Murray CA, Day SJ, Kleiner K, Clarke SJ, Compton RG. Elektrochemische In‐situ‐Röntgenbeugung: Eine präzise Methode zur Navigation in Phasendiagrammen enthüllt β‐Fe 1+xSe als Supraleiter für alle x. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201907426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Bertold Rasche
- Department of Chemistry University of Oxford Oxford OX1 3QZ Großbritannien
| | - Minjun Yang
- Department of Chemistry University of Oxford Oxford OX1 3QZ Großbritannien
| | - Lothar Nikonow
- Department of Chemistry University of Oxford Oxford OX1 3QZ Großbritannien
| | - Joshaniel F. K. Cooper
- ISIS Neutron and Muon Source Rutherford Appleton Laboratory Harwell Campus Didcot OX11 0QX Großbritannien
| | - Claire A. Murray
- Diamond Light Source Harwell Campus Didcot OX11 0QX Großbritannien
| | - Sarah J. Day
- Diamond Light Source Harwell Campus Didcot OX11 0QX Großbritannien
| | - Karin Kleiner
- Diamond Light Source Harwell Campus Didcot OX11 0QX Großbritannien
| | - Simon J. Clarke
- Department of Chemistry University of Oxford Oxford OX1 3QZ Großbritannien
| | - Richard G. Compton
- Department of Chemistry University of Oxford Oxford OX1 3QZ Großbritannien
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15
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Liu J, Zhang S, Li M, Sang L, Li Z, Cheng Z, Zhao W, Feng J, Li C, Zhang P, Dou S, Wang X, Zhou L. Boosting Superconducting Properties of Fe(Se, Te) via Dual-Oscillation Phenomena Induced by Fluorine Doping. ACS APPLIED MATERIALS & INTERFACES 2019; 11:18825-18832. [PMID: 31007006 DOI: 10.1021/acsami.9b02469] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Fluorine-doped Fe(Se, Te) has been successfully synthesized using the melting method. A dual-oscillation effect was found in the F-doped sample, which combined both microstructural oscillation and chemical compositional oscillation. The microstructural oscillation could be attributed to alternate growth of tetragonal β-Fe(Se, Te) and hexagonal δ-Fe(Se, Te), which formed a pearlite-like structure and led to the enhancement of δ l flux pinning due to the alternating distributed nonsuperconducting δ-Fe(Se, Te) phase. The chemical compositional oscillations in β-Fe(Se, Te) phase were because of the inhomogeneously distributed Se and Te, which changes the pinning mechanism from surface pinning in the undoped sample to Δκ pinning in the 5% F-doped one. As a result, the critical current, upper critical field, and thermally activated flux-flow activation energy of FeSe0.45Te0.5F0.05 were enhanced by 7, 2, and 3 times, respectively. Our work revealed the physical insights into F-doping resulting in high-performance Fe(Se, Te) superconductors and inspired a new approach to optimize superconductivities in iron-based superconductors through phase and element manipulations.
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Affiliation(s)
- Jixing Liu
- School of Materials Science and Engineering , Northeastern University , Shenyang 110819 , China
- Superconducting Materials Research Center , Northwest Institute for Nonferrous Metal Research , Xi'an 710016 , China
- Institute for Superconducting and Electronic Materials, Faculty of Engineering, Australian Institute for Innovative Materials , University of Wollongong , Wollongong , NSW 2500 , Australia
| | - Shengnan Zhang
- Superconducting Materials Research Center , Northwest Institute for Nonferrous Metal Research , Xi'an 710016 , China
| | - Meng Li
- Institute for Superconducting and Electronic Materials, Faculty of Engineering, Australian Institute for Innovative Materials , University of Wollongong , Wollongong , NSW 2500 , Australia
| | - Lina Sang
- Institute for Superconducting and Electronic Materials, Faculty of Engineering, Australian Institute for Innovative Materials , University of Wollongong , Wollongong , NSW 2500 , Australia
| | - Zhi Li
- Institute for Superconducting and Electronic Materials, Faculty of Engineering, Australian Institute for Innovative Materials , University of Wollongong , Wollongong , NSW 2500 , Australia
| | - Zhenxiang Cheng
- Institute for Superconducting and Electronic Materials, Faculty of Engineering, Australian Institute for Innovative Materials , University of Wollongong , Wollongong , NSW 2500 , Australia
| | - Weiyao Zhao
- Institute for Superconducting and Electronic Materials, Faculty of Engineering, Australian Institute for Innovative Materials , University of Wollongong , Wollongong , NSW 2500 , Australia
| | - Jianqing Feng
- Superconducting Materials Research Center , Northwest Institute for Nonferrous Metal Research , Xi'an 710016 , China
| | - Chengshan Li
- School of Materials Science and Engineering , Northeastern University , Shenyang 110819 , China
- Superconducting Materials Research Center , Northwest Institute for Nonferrous Metal Research , Xi'an 710016 , China
| | - Pingxiang Zhang
- School of Materials Science and Engineering , Northeastern University , Shenyang 110819 , China
- Superconducting Materials Research Center , Northwest Institute for Nonferrous Metal Research , Xi'an 710016 , China
| | - Shixue Dou
- Institute for Superconducting and Electronic Materials, Faculty of Engineering, Australian Institute for Innovative Materials , University of Wollongong , Wollongong , NSW 2500 , Australia
| | - Xiaolin Wang
- Institute for Superconducting and Electronic Materials, Faculty of Engineering, Australian Institute for Innovative Materials , University of Wollongong , Wollongong , NSW 2500 , Australia
| | - Lian Zhou
- School of Materials Science and Engineering , Northeastern University , Shenyang 110819 , China
- Superconducting Materials Research Center , Northwest Institute for Nonferrous Metal Research , Xi'an 710016 , China
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16
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Fallon MJ, Martinolich AJ, Maughan AE, Gallington LC, Neilson JR. Low-temperature synthesis of superconducting iron selenide using a triphenylphosphine flux. Dalton Trans 2019; 48:16298-16303. [DOI: 10.1039/c9dt03723c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A low-temperature synthesis of iron selenide using molten triphenylphosphine demonstrates the use of an organic flux in solid-state synthesis.
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17
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Krzton-Maziopa A, Pesko E, Puzniak R. Superconducting selenides intercalated with organic molecules: synthesis, crystal structure, electric and magnetic properties, superconducting properties, and phase separation in iron based-chalcogenides and hybrid organic-inorganic superconductors. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:243001. [PMID: 29664412 DOI: 10.1088/1361-648x/aabeb5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Layered iron-based superconducting chalcogenides intercalated with molecular species are the subject of intensive studies, especially in the field of solid state chemistry and condensed matter physics, because of their intriguing chemistry and tunable electric and magnetic properties. Considerable progress in the research, revealing superconducting inorganic-organic hybrid materials with transition temperatures to superconducting state, T c, up to 46 K, has been brought in recent years. These novel materials are synthesized by low-temperature intercalation of molecular species, such as solvates of alkali metals and nitrogen-containing donor compounds, into layered FeSe-type structure. Both the chemical nature as well as orientation of organic molecules between the layers of inorganic host, play an important role in structural modifications and may be used for fine tuning of superconducting properties. Furthermore, a variety of donor species compatible with alkali metals, as well as the possibility of doping also in the host structure (either on Fe or Se sites), makes this system quite flexible and gives a vast array of new materials with tunable electric and magnetic properties. In this review, the main aspects of intercalation chemistry are discussed with a particular attention paid to the influence of the unique nature of intercalating species on the crystal structure and physical properties of the hybrid inorganic-organic materials. To get a full picture of these materials, a comprehensive description of the most effective chemical and electrochemical methods, utilized for synthesis of intercalated species, with critical evaluation of their strong and weak points, related to feasibility of synthesis, phase purity, crystal size and morphology of final products, is included as well.
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Affiliation(s)
- Anna Krzton-Maziopa
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, PL-00-664 Warsaw, Poland
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18
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Brehm JA, Lin J, Zhou J, Sims H, Liu Z, Pantelides ST, Suenaga K. Electron-Beam-Induced Synthesis of Hexagonal 1 H-MoSe 2 from Square β-FeSe Decorated with Mo Adatoms. NANO LETTERS 2018; 18:2016-2020. [PMID: 29388778 DOI: 10.1021/acs.nanolett.7b05457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Two-dimensional (2D) materials have generated interest in the scientific community because of the advanced electronic applications they might offer. Powerful electron beam microscopes have been used not only to evaluate the structures of these materials but also to manipulate them by forming vacancies, nanofragments, and nanowires or joining nanoislands together. In this work, we show that the electron beam in a scanning transmission electron microscope (STEM) can be used in yet another way: to mediate the synthesis of 2D 1 H-MoSe2 from Mo-decorated 2D β-FeSe and simultaneously image the process on the atomic scale. This is quite remarkable given the different crystal structures of the reactant (square lattice β-FeSe) and the product (hexagonal lattice 1 H-MoSe2). The feasibility of the transformation was first explored by theoretical calculations that predicted that the reaction is exothermic. Furthermore, a theoretical reaction path to forming a stable 1 H-MoSe2 nucleation kernel within pure β-FeSe was found, demonstrating that the pertinent energy barriers are smaller than the energy supplied by the STEM electron beam.
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Affiliation(s)
- John A Brehm
- Department of Physics and Astronomy , Vanderbilt University , Nashville , Tennessee 37235 , United States
- Materials Science and Technology Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Junhao Lin
- National Institute of Advanced Industrial Science and Technology (AIST) , AIST Central 5 , Tsukuba 305-8565 , Japan
| | - Jiadong Zhou
- Center for Programmable Materials, School of Materials Science and Engineering , Nanyang Technological University , 639798 Singapore
| | - Hunter Sims
- Department of Physics and Astronomy , Vanderbilt University , Nashville , Tennessee 37235 , United States
- Materials Science and Technology Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Zheng Liu
- Center for Programmable Materials, School of Materials Science and Engineering , Nanyang Technological University , 639798 Singapore
- Centre for Micro-/Nano-electronics (NOVITAS), School of Electrical & Electronic Engineering , Nanyang Technological University , 50 Nanyang Avenue , 639798 Singapore
- CINTRA CNRS/NTU/THALES, UMI 3288, Research Techno Plaza , 50 Nanyang Drive, Border X Block, Level 6 , 637553 Singapore
| | - Sokrates T Pantelides
- Department of Physics and Astronomy , Vanderbilt University , Nashville , Tennessee 37235 , United States
- Materials Science and Technology Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
- Department of Electrical Engineering and Computer Science , Vanderbilt University , Nashville , Tennessee 37235 , United States
| | - Kazu Suenaga
- National Institute of Advanced Industrial Science and Technology (AIST) , AIST Central 5 , Tsukuba 305-8565 , Japan
- Department of Mechanical Engineering , The University of Tokyo , Tokyo 113-8656 , Japan
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19
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Böhmer AE, Kreisel A. Nematicity, magnetism and superconductivity in FeSe. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:023001. [PMID: 29240560 DOI: 10.1088/1361-648x/aa9caa] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Iron-based superconductors are well known for their complex interplay between structure, magnetism and superconductivity. FeSe offers a particularly fascinating example. This material has been intensely discussed because of its extended nematic phase, whose relationship with magnetism is not obvious. Superconductivity in FeSe is highly tunable, with the superconducting transition temperature, T c, ranging from 8 K in bulk single crystals at ambient pressure to almost 40 K under pressure or in intercalated systems, and to even higher temperatures in thin films. In this topical review, we present an overview of nematicity, magnetism and superconductivity, and discuss the interplay of these phases in FeSe. We focus on bulk FeSe and the effects of physical pressure and chemical substitutions as tuning parameters. The experimental results are discussed in the context of the well-studied iron-pnictide superconductors and interpretations from theoretical approaches are presented.
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Affiliation(s)
- Anna E Böhmer
- Ames Laboratory, US DOE, Ames, IA 50011, United States of America
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20
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Chareev D, Ovchenkov Y, Shvanskaya L, Kovalskii A, Abdel-Hafiez M, Trainer DJ, Lechner EM, Iavarone M, Volkova O, Vasiliev A. Single crystal growth, transport and scanning tunneling microscopy and spectroscopy of FeSe1−xSx. CrystEngComm 2018. [DOI: 10.1039/c8ce00074c] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
“Ampoule in ampoule” design to grow single crystals of FeSe1−xSx.
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Affiliation(s)
- Dmitriy Chareev
- RAS
- Institute of Experimental Mineralogy
- Chernogolovka 123456
- Russia
- Ural Federal University
| | | | - Larisa Shvanskaya
- Lomonosov Moscow State University
- Moscow 119991
- Russia
- National University of Science and Technology “MISiS”
- Moscow 119049
| | - Andrey Kovalskii
- National University of Science and Technology “MISiS”
- Moscow 119049
- Russia
| | - Mahmoud Abdel-Hafiez
- National University of Science and Technology “MISiS”
- Moscow 119049
- Russia
- Goethe University Frankfurt
- Frankfurt am Main 60438
| | | | | | | | - Olga Volkova
- Ural Federal University
- Ekaterinburg 620002
- Russia
- Lomonosov Moscow State University
- Moscow 119991
| | - Alexander Vasiliev
- Lomonosov Moscow State University
- Moscow 119991
- Russia
- National University of Science and Technology “MISiS”
- Moscow 119049
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21
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Zhao X, Wang CZ, Kim M, Ho KM. Fe-Cluster Compounds of Chalcogenides: Candidates for Rare-Earth-Free Permanent Magnet and Magnetic Nodal-Line Topological Material. Inorg Chem 2017; 56:14577-14583. [PMID: 29131940 DOI: 10.1021/acs.inorgchem.7b02318] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Fe-cluster-based crystal structures are predicted for chalcogenides Fe3X4 (X = S, Se, Te) using an adaptive genetic algorithm. Topologically different from the well-studied layered structures of iron chalcogenides, the newly predicted structures consist of Fe clusters that are either separated by the chalcogen atoms or connected via sharing of the vertex Fe atoms. Using first-principles calculations, we demonstrate that these structures have competitive or even lower formation energies than the experimentally synthesized Fe3X4 compounds and exhibit interesting magnetic and electronic properties. In particular, we show that Fe3Te4 can be a good candidate as a rare-earth-free permanent magnet and Fe3S4 can be a magnetic nodal-line topological material.
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Affiliation(s)
- Xin Zhao
- Department of Physics and Astronomy, Iowa State University , Ames, Iowa 50011, United States
| | - Cai-Zhuang Wang
- Department of Physics and Astronomy, Iowa State University , Ames, Iowa 50011, United States
| | - Minsung Kim
- Ames Laboratory, U.S. Department of Energy , Ames, Iowa 50011, United States
| | - Kai-Ming Ho
- Department of Physics and Astronomy, Iowa State University , Ames, Iowa 50011, United States
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22
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Origin of the emergence of higher T c than bulk in iron chalcogenide thin films. Sci Rep 2017; 7:9994. [PMID: 28855591 PMCID: PMC5577040 DOI: 10.1038/s41598-017-10383-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 08/08/2017] [Indexed: 12/01/2022] Open
Abstract
Fabrication of epitaxial FeSexTe1−x thin films using pulsed laser deposition (PLD) enables improving their superconducting transition temperature (Tc) by more than ~40% than their bulk Tc. Intriguingly, Tc enhancement in FeSexTe1−x thin films has been observed on various substrates and with different Se content, x. To date, various mechanisms for Tc enhancement have been reported, but they remain controversial in universally explaining the Tc improvement in the FeSexTe1−x films. In this report, we demonstrate that the controversies over the mechanism of Tc enhancement are due to the abnormal changes in the chalcogen ratio (Se:Te) during the film growth and that the previously reported Tc enhancement in FeSe0.5Te0.5 thin films is caused by a remarkable increase of Se content. Although our FeSexTe1−x thin films were fabricated via PLD using a Fe0.94Se0.45Te0.55 target, the precisely measured composition indicates a Se-rich FeSexTe1−x (0.6 < x < 0.8) as ascertained through accurate compositional analysis by both wavelength dispersive spectroscopy (WDS) and Rutherford backscattering spectrometry (RBS). We suggest that the origin of the abnormal composition change is the difference in the thermodynamic properties of ternary FeSexTe1−x, based on first principle calculations.
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23
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Hussain RA, Badshah A, Lal B. Fabrication, characterization and applications of iron selenide. J SOLID STATE CHEM 2016. [DOI: 10.1016/j.jssc.2016.08.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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24
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Chareev DA, Volkova OS, Geringer NV, Koshelev AV, Nekrasov AN, Osadchii VO, Osadchii EG, Filimonova ON. Synthesis of chalcogenide and pnictide crystals in salt melts using a steady-state temperature gradient. CRYSTALLOGR REP+ 2016. [DOI: 10.1134/s1063774516030068] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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25
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Krzton-Maziopa A, Svitlyk V, Pomjakushina E, Puzniak R, Conder K. Superconductivity in alkali metal intercalated iron selenides. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:293002. [PMID: 27248118 DOI: 10.1088/0953-8984/28/29/293002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Alkali metal intercalated iron selenide superconductors A x Fe2-y Se2 (where A = K, Rb, Cs, Tl/K, and Tl/Rb) are characterized by several unique properties, which were not revealed in other superconducting materials. The compounds crystallize in overall simple layered structure with FeSe layers intercalated with alkali metal. The structure turned out to be pretty complex as the existing Fe-vacancies order below ~550 K, which further leads to an antiferromagnetic ordering with Néel temperature fairly above room temperature. At even lower temperatures a phase separation is observed. While one of these phases stays magnetic down to the lowest temperatures the second is becoming superconducting below ~30 K. All these effects give rise to complex relationships between the structure, magnetism and superconductivity. In particular the iron vacancy ordering, linked with a long-range magnetic order and a mesoscopic phase separation, is assumed to be an intrinsic property of the system. Since the discovery of superconductivity in those compounds in 2010 they were investigated very extensively. Results of the studies conducted using a variety of experimental techniques and performed during the last five years were published in hundreds of reports. The present paper reviews scientific work concerning methods of synthesis and crystal growth, structural and superconducting properties as well as pressure investigations.
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Affiliation(s)
- A Krzton-Maziopa
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, PL-00-664 Warsaw, Poland
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26
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Gorina JI, Kaljuzhnaia GA, Golubkov MV, Rodin VV, Romanova TA, Sentjurina NN, Chernook SG. Evolution of the structural and superconducting properties of FeSe crystals upon long-term storage. CRYSTALLOGR REP+ 2016. [DOI: 10.1134/s1063774516020085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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27
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Vasconcelos HMDN, Eddrief M, Zheng Y, Demaille D, Hidki S, Fonda E, Novikova A, Fujii J, Torelli P, Salles BR, Vobornik I, Panaccione G, de Oliveira AJA, Marangolo M, Vidal F. Magnetically Hard Fe3Se4 Embedded in Bi2Se3 Topological Insulator Thin Films Grown by Molecular Beam Epitaxy. ACS NANO 2016; 10:1132-1138. [PMID: 26653134 DOI: 10.1021/acsnano.5b06430] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We investigated the structural, magnetic, and electronic properties of Bi2Se3 epilayers containing Fe grown on GaAs(111) by molecular beam epitaxy. It is shown that, in the window of growth parameters leading to Bi2Se3 epilayers with optimized quality, Fe atom clustering leads to the formation of FexSey inclusions. These objects have platelet shape and are embedded within Bi2Se3. Monoclinic Fe3Se4 is identified as the main secondary phase through detailed structural measurements. Due to the presence of the hard ferrimagnetic Fe3Se4 inclusions, the system exhibits a very large coercive field at low temperature and room temperature magnetic ordering. Despite this composite structure and the proximity of a magnetic phase, the surface electronic structure of Bi2Se3 is preserved, as shown by the persistence of a gapless Dirac cone at Γ.
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Affiliation(s)
- Hugo Menezes do Nascimento Vasconcelos
- Sorbonne Universités , UPMC Univ Paris 06, CNRS-UMR 7588, Institut des NanoSciences de Paris, F-75005 Paris, France
- Departamento de Física, Universidade Federal de São Carlos , CP 676, 13565-905 São Carlos, SP, Brazil
| | - Mahmoud Eddrief
- Sorbonne Universités , UPMC Univ Paris 06, CNRS-UMR 7588, Institut des NanoSciences de Paris, F-75005 Paris, France
| | - Yunlin Zheng
- Sorbonne Universités , UPMC Univ Paris 06, CNRS-UMR 7588, Institut des NanoSciences de Paris, F-75005 Paris, France
| | - Dominique Demaille
- Sorbonne Universités , UPMC Univ Paris 06, CNRS-UMR 7588, Institut des NanoSciences de Paris, F-75005 Paris, France
| | - Sarah Hidki
- Sorbonne Universités , UPMC Univ Paris 06, CNRS-UMR 7588, Institut des NanoSciences de Paris, F-75005 Paris, France
| | - Emiliano Fonda
- Synchrotron Soleil , L'Orme des Merisiers Saint-Aubin BP 48, 91192 Gif-sur-Yvette Cedex, France
| | - Anastasiia Novikova
- Synchrotron Soleil , L'Orme des Merisiers Saint-Aubin BP 48, 91192 Gif-sur-Yvette Cedex, France
| | - Jun Fujii
- Istituto Officina dei Materiali (IOM) - CNR, Laboratorio TASC, in Area Science Park, S.S.14, Km 163.5, I-34149 Trieste, Italy
| | - Piero Torelli
- Istituto Officina dei Materiali (IOM) - CNR, Laboratorio TASC, in Area Science Park, S.S.14, Km 163.5, I-34149 Trieste, Italy
| | - Benjamin Rache Salles
- Istituto Officina dei Materiali (IOM) - CNR, Laboratorio TASC, in Area Science Park, S.S.14, Km 163.5, I-34149 Trieste, Italy
- Instituto de Física, Universidade Federal do Rio de Janeiro , 21941-972 Rio de Janeiro, RJ, Brazil
| | - Ivana Vobornik
- Istituto Officina dei Materiali (IOM) - CNR, Laboratorio TASC, in Area Science Park, S.S.14, Km 163.5, I-34149 Trieste, Italy
| | - Giancarlo Panaccione
- Istituto Officina dei Materiali (IOM) - CNR, Laboratorio TASC, in Area Science Park, S.S.14, Km 163.5, I-34149 Trieste, Italy
| | | | - Massimiliano Marangolo
- Sorbonne Universités , UPMC Univ Paris 06, CNRS-UMR 7588, Institut des NanoSciences de Paris, F-75005 Paris, France
| | - Franck Vidal
- Sorbonne Universités , UPMC Univ Paris 06, CNRS-UMR 7588, Institut des NanoSciences de Paris, F-75005 Paris, France
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28
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Hacisalihoglu MY, Paris E, Joseph B, Yanmaz E, Saini NL. The nanoscale structure and unoccupied valence electronic states in FeSe1-xTex chalcogenides probed by X-ray absorption measurements. Phys Chem Chem Phys 2015; 17:18131-7. [PMID: 26099493 DOI: 10.1039/c5cp01740h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have studied the nanoscale structure and unoccupied electronic states in FeSe1-xTex by a combined analysis of Se K, Te L1 and Fe K-edges X-ray absorption measurements. Extended X-ray absorption fine structure (EXAFS) results show that iron-chalcogen (Fe-Se and Fe-Te) distances in ternary FeSe1-xTex are similar to those measured for binary FeSe and FeTe. The local Fe-Se/Te distances determined by different absorption edges fit well in the characteristic Z-plot of random alloys, providing unambiguous support to the inhomogeneous nanoscale structure of the ternary FeSe1-xTex system. X-ray absorption near-edge structure (XANES) spectra reveal a gradual evolution of the unoccupied valence electronic states as a function of Te-substitution in FeSe1-xTex. The Fe 3d-Se 4p/Te 5p hybridization is found to decrease with Te-substitution, accompanied by an increase in unoccupied Se 4p states and a decrease in unoccupied Te 5p states. The results are discussed in the frame of local inhomogeneity in the FeSe1-xTex system driven by random alloying of Se/Te atoms.
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Affiliation(s)
- M Y Hacisalihoglu
- Dipartimento di Fisica, Universitá di Roma "La Sapienza", P. le Aldo Moro 2, 00185 Rome, Italy.
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29
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Guo Z, Li S, Zhang L, Han B, Zhang H, Yuan W. Phase assemblages of the K–Fe–Se ternary system (x K < 33.3 %) and the metastability of superconducting phase in this area. MONATSHEFTE FUR CHEMIE 2015. [DOI: 10.1007/s00706-015-1489-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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30
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Koz C, Schmidt M, Borrmann H, Burkhardt U, Röβler S, Carrillo-Cabrera W, Schnelle W, Schwarz U, Grin Y. Synthesis and Crystal Growth of Tetragonal β-Fe1.00Se. Z Anorg Allg Chem 2014. [DOI: 10.1002/zaac.201300670] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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31
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Abstract
Several superconducting transition temperatures in the range of 30-46 K were reported in the recently discovered intercalated FeSe system (A1-xFe2-ySe2, A = K, Rb, Cs, Tl). Although the superconducting phases were not yet conclusively decided, more than one magnetic phase with particular orders of iron vacancy and/or potassium vacancy were identified, and some were argued to be the parent phase. Here we show the discovery of the presence and ordering of iron vacancy in nonintercalated FeSe (PbO-type tetragonal β-Fe1-xSe). Three types of iron-vacancy order were found through analytical electron microscopy, and one was identified to be nonsuperconducting and magnetic at low temperature. This discovery suggests that the rich-phases found in A1-xFe2-ySe2 are not exclusive in Fe-Se and related superconductors. In addition, the magnetic β-Fe1-xSe phases with particular iron-vacancy orders are more likely to be the parent phase of the FeSe superconducting system instead of the previously assigned β-Fe1+δTe.
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32
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Wu MK, Wang MJ, Yeh KW. Recent advances in β-FeSe 1-x and related superconductors. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2013; 14:014402. [PMID: 27877558 PMCID: PMC5090576 DOI: 10.1088/1468-6996/14/1/014402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 11/20/2012] [Indexed: 06/06/2023]
Abstract
It has been more than four years since the discovery of β-FeSe1-x superconductors. Through the efforts of many outstanding research groups, unprecedented advances in the field have been achieved. High-quality single crystals of β-FeSe1-x and related compounds have been prepared by various techniques, allowing us to explore in detail the physical properties of this class of materials. Detailed characterizations of the structure and properties of these crystals have helped us to understand the origin of superconductivity in β-FeSe1-x . The occurrence of superconductivity is associated with the low-temperature structure distortion, which is accompanied by several anomalies. Recent measurements on quasiparticle and acoustic phonon dynamics with respect to the orbital modification in β-FeSe1-x suggest the opening of an energy gap below 130-140 K, accompanied by a coincident transfer of optical spectral weight in the visible range and alterations in transport properties. These observations provide convincing evidence that the modification of the electronic structure occurs prior to the lattice distortion. They further suggest that the high-temperature gap and the lattice symmetry breaking are driven by short-range orbital and/or charge orders.
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Affiliation(s)
- Maw-Kuen Wu
- Department of Physics, National Dong-Hwa University, Hualien, Taiwan
- Institute of Physics, Academia Sinica, Taipei, Taiwan
| | - Ming-Jye Wang
- Institute of Physics, Academia Sinica, Taipei, Taiwan
- Institute of Astronomy and Astrophysics, Academia Sinica, Taipei, Taiwan
| | - Kuo-Wei Yeh
- Institute of Physics, Academia Sinica, Taipei, Taiwan
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33
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Grechnev GE, Panfilov AS, Desnenko VA, Fedorchenko AV, Gnatchenko SL, Chareev DA, Volkova OS, Vasiliev AN. Magnetic properties of superconducting FeSe in the normal state. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:046004. [PMID: 23238440 DOI: 10.1088/0953-8984/25/4/046004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A detailed magnetization study for the novel FeSe superconductor is carried out to investigate the behavior of the intrinsic magnetic susceptibility χ in the normal state with temperature and under hydrostatic pressure. The temperature dependences of χ and its anisotropy Δχ = χ([parallel]) - χ([perpendicular]) are measured for FeSe single crystals in the temperature range 4.2-300 K, and a substantial growth of susceptibility with temperature is revealed. The observed anisotropy Δχ is very large and comparable to the averaged susceptibility at low temperatures. For a polycrystalline sample of FeSe, the significant pressure effect on χ is determined to be essentially dependent on temperature. Ab initio calculations of the pressure-dependent electronic structure and magnetic susceptibility indicate that FeSe is close to magnetic instability, with dominating enhanced spin paramagnetism. The calculated paramagnetic susceptibility exhibits a strong dependence on the unit cell volume and especially on the height Z of chalcogen species from the Fe plane. The change of Z under pressure determines a large positive pressure effect on χ, which is observed at low temperatures. It is shown that the literature experimental data on the strong and nonmonotonic pressure dependence of the superconducting transition temperature in FeSe correlate qualitatively with the calculated behavior of the density of electronic states at the Fermi level.
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Affiliation(s)
- G E Grechnev
- B Verkin Institute for Low Temperature Physics and Engineering, National Academy of Sciences of Ukraine, 61103 Kharkov, Ukraine.
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34
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Chareev D, Osadchii E, Kuzmicheva T, Lin JY, Kuzmichev S, Volkova O, Vasiliev A. Single crystal growth and characterization of tetragonal FeSe1−x superconductors. CrystEngComm 2013. [DOI: 10.1039/c2ce26857d] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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35
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Gorina JI, Kaluzhnaya GA, Golubkov MV, Rodin VV, Sentjurina NN, Chernook SG. Growth and structure of superconducting FeSe crystals. CRYSTALLOGR REP+ 2012. [DOI: 10.1134/s1063774512040050] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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36
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Nitsche F, Goltz T, Klauss HH, Isaeva A, Müller U, Schnelle W, Simon P, Doert T, Ruck M. Room-Temperature Synthesis, Hydrothermal Recrystallization, and Properties of Metastable Stoichiometric FeSe. Inorg Chem 2012; 51:7370-6. [DOI: 10.1021/ic300798p] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- F. Nitsche
- Department
of Chemistry and
Food Chemistry, Technische Universität Dresden, D-01062 Dresden, Germany
| | - T. Goltz
- Institute of Solid State Physics, Technische Universität Dresden, D-01062 Dresden,
Germany
| | - H.-H. Klauss
- Institute of Solid State Physics, Technische Universität Dresden, D-01062 Dresden,
Germany
| | - A. Isaeva
- Department
of Chemistry and
Food Chemistry, Technische Universität Dresden, D-01062 Dresden, Germany
| | - U. Müller
- Department
of Chemistry and
Food Chemistry, Technische Universität Dresden, D-01062 Dresden, Germany
| | - W. Schnelle
- Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
| | - P. Simon
- Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
| | - Th. Doert
- Department
of Chemistry and
Food Chemistry, Technische Universität Dresden, D-01062 Dresden, Germany
| | - M. Ruck
- Department
of Chemistry and
Food Chemistry, Technische Universität Dresden, D-01062 Dresden, Germany
- Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
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37
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Malavasi L, Margadonna S. Structure–properties correlations in Fe chalcogenide superconductors. Chem Soc Rev 2012; 41:3897-911. [DOI: 10.1039/c2cs35021a] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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38
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Eichhöfer A, Buth G, Dolci F, Fink K, Mole RA, Wood PT. Homoleptic 1-D iron selenolate complexes—synthesis, structure, magnetic and thermal behaviour of 1∞[Fe(SeR)2] (R = Ph, Mes). Dalton Trans 2011; 40:7022-32. [DOI: 10.1039/c1dt10089k] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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39
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Kurmaev EZ, McLeod JA, Skorikov NA, Finkelstein LD, Moewes A, Korotin MA, Izyumov YA, Xie YL, Wu G, Chen XH. Structural models of FeSe(x). JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:435702. [PMID: 21832444 DOI: 10.1088/0953-8984/21/43/435702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Two different structural models for non-stoichiometric FeSe(x) are examined and compared with soft x-ray spectroscopy findings for FeSe(x) (x = 0.85, 0.50). A structural model of tetragonal FeSe with excess interstitial Fe gives better agreement with experiment than a structural model of tetragonal FeSe with Se vacancies. This interstitial Fe increases the number of 3d states at the Fermi level. We find evidence that large non-stoichiometric ratios of Fe:Se, such as that of FeSe(0.50), yield clusters of pure Fe in the crystal structure.
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Affiliation(s)
- E Z Kurmaev
- Institute of Metal Physics, Russian Academy of Sciences-Ural Division, 620219 Yekaterinburg, Russia
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40
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Williams AJ, McQueen TM, Ksenofontov V, Felser C, Cava RJ. The metal-insulator transition in Fe(1.01-x)Cu(x)Se. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:305701. [PMID: 21828556 DOI: 10.1088/0953-8984/21/30/305701] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Iron selenide, Fe(1.01)Se, the layered parent compound of the recently discovered superconducting arsenide family, has previously been shown to be non-magnetic and superconducting with a critical temperature of 8 K. Here we show that copper can be substituted at the iron site in Fe(1.01)Se up to a solubility limit of 20-30%, after which a first-order transition to the three-dimensional CuFeSe(2) structure type is observed. As little as 1.5% copper is sufficient to suppress the superconductivity, and 4% drives the system through a metal-insulator transition. A local magnetic moment is introduced, which maximizes near 12% doping, where a spin-glass transition near 15 K is observed.
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Affiliation(s)
- A J Williams
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
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41
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Ma F, Ji W, Hu J, Lu ZY, Xiang T. First-principles calculations of the electronic structure of tetragonal alpha-FeTe and alpha-FeSe crystals: evidence for a bicollinear antiferromagnetic order. PHYSICAL REVIEW LETTERS 2009; 102:177003. [PMID: 19518816 DOI: 10.1103/physrevlett.102.177003] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2008] [Indexed: 05/27/2023]
Abstract
By the first-principles electronic structure calculations, we find that the ground state of PbO-type tetragonal alpha-FeTe is in a bicollinear antiferromagnetic order, in which the Fe local moments (approximately 2.5 microB) align ferromagnetically along a diagonal direction and antiferromagnetically along the other diagonal direction on the Fe square lattice. This novel bicollinear order results from the interplay among the nearest, the next-nearest, and the next-next-nearest neighbor superexchange interactions, mediated by Te 5p band. In contrast, the ground state of alpha-FeSe is in a collinear antiferromagnetic order, similar to those in LaFeAsO and BaFe2As2. This finding sheds new light on the origin of magnetic ordering in Fe-based superconductors.
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Affiliation(s)
- Fengjie Ma
- Department of Physics, Renmin University of China, Beijing 100872, China
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42
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Hsu FC, Luo JY, Yeh KW, Chen TK, Huang TW, Wu PM, Lee YC, Huang YL, Chu YY, Yan DC, Wu MK. Superconductivity in the PbO-type structure alpha-FeSe. Proc Natl Acad Sci U S A 2008; 105:14262-4. [PMID: 18776050 PMCID: PMC2531064 DOI: 10.1073/pnas.0807325105] [Citation(s) in RCA: 521] [Impact Index Per Article: 32.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2008] [Indexed: 11/18/2022] Open
Abstract
The recent discovery of superconductivity with relatively high transition temperature (Tc) in the layered iron-based quaternary oxypnictides La[O(1-x)F(x)] FeAs by Kamihara et al. [Kamihara Y, Watanabe T, Hirano M, Hosono H (2008) Iron-based layered superconductor La[O1-xFx] FeAs (x = 0.05-0.12) with Tc = 26 K. J Am Chem Soc 130:3296-3297.] was a real surprise and has generated tremendous interest. Although superconductivity exists in alloy that contains the element Fe, LaOMPn (with M = Fe, Ni; and Pn = P and As) is the first system where Fe plays the key role to the occurrence of superconductivity. LaOMPn has a layered crystal structure with an Fe-based plane. It is quite natural to search whether there exists other Fe based planar compounds that exhibit superconductivity. Here, we report the observation of superconductivity with zero-resistance transition temperature at 8 K in the PbO-type alpha-FeSe compound. A key observation is that the clean superconducting phase exists only in those samples prepared with intentional Se deficiency. FeSe, compared with LaOFeAs, is less toxic and much easier to handle. What is truly striking is that this compound has the same, perhaps simpler, planar crystal sublattice as the layered oxypnictides. Therefore, this result provides an opportunity to better understand the underlying mechanism of superconductivity in this class of unconventional superconductors.
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Affiliation(s)
- Fong-Chi Hsu
- *Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan; and
| | - Jiu-Yong Luo
- *Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan
| | - Kuo-Wei Yeh
- *Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan
| | - Ta-Kun Chen
- *Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan
| | - Tzu-Wen Huang
- *Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan
| | - Phillip M. Wu
- Department of Physics, Duke University, Durham, NC 27708
| | - Yong-Chi Lee
- *Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan
| | - Yi-Lin Huang
- *Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan
| | - Yan-Yi Chu
- *Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan; and
| | - Der-Chung Yan
- *Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan
| | - Maw-Kuen Wu
- *Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan
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