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Title: Lattice parameters guide superconductivity in iron-arsenides

Abstract

The discovery of superconducting materials has led to their use in modern technological marvels, such as magnetic field sensors in MRI machines, powerful research magnets, and high-speed trains. Despite such applications, the uses of superconductors are not widespread due to high cooling costs. Since the discovery of Cu- and Fe-based high-temperature superconductors (HTS), numerous studies have tried to explain and understand the superconducting phenomenon. While no exact explanations are given, several trends are reported in relation to the materials basis in magnetism and spin excitations. In fact, most HTS have antiferromagnetic undoped ‘parent’ materials that undergo a superconducting transition upon small chemical substitutions in them. As it is currently unclear which ‘dopants’ can favor of superconductivity, this manuscript investigates crystal structure changes upon chemical substitutions, to find clues in lattice parameters for the superconducting occurrence. We review the chemical substitution effects on the crystal lattice of iron-based materials (2008 to present). We note that (a) HTS compounds have nearly tetragonal structures with a-lattice parameter close to 4 Å, and (b) superconductivity can depend strongly on the c-lattice parameter changes with chemical substitution. For example, a decrease in c-lattice parameter is required to induce ‘in-plane’ superconductivity. The review of lattice parametermore » trends in iron-based superconductors presented here, should guide synthesis of new materials and give clues for superconductivity.« less

Authors:
 [1];  [2]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of California, San Diego, CA (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1376515
Grant/Contract Number:
AC05-00OR22725
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of Physics. Condensed Matter
Additional Journal Information:
Journal Volume: 29; Journal Issue: 8; Journal ID: ISSN 0953-8984
Publisher:
IOP Publishing
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Konzen, Lance M. N., and Sefat, Athena S. Lattice parameters guide superconductivity in iron-arsenides. United States: N. p., 2017. Web. doi:10.1088/1361-648X/aa4e03.
Konzen, Lance M. N., & Sefat, Athena S. Lattice parameters guide superconductivity in iron-arsenides. United States. doi:10.1088/1361-648X/aa4e03.
Konzen, Lance M. N., and Sefat, Athena S. Thu . "Lattice parameters guide superconductivity in iron-arsenides". United States. doi:10.1088/1361-648X/aa4e03. https://www.osti.gov/servlets/purl/1376515.
@article{osti_1376515,
title = {Lattice parameters guide superconductivity in iron-arsenides},
author = {Konzen, Lance M. N. and Sefat, Athena S.},
abstractNote = {The discovery of superconducting materials has led to their use in modern technological marvels, such as magnetic field sensors in MRI machines, powerful research magnets, and high-speed trains. Despite such applications, the uses of superconductors are not widespread due to high cooling costs. Since the discovery of Cu- and Fe-based high-temperature superconductors (HTS), numerous studies have tried to explain and understand the superconducting phenomenon. While no exact explanations are given, several trends are reported in relation to the materials basis in magnetism and spin excitations. In fact, most HTS have antiferromagnetic undoped ‘parent’ materials that undergo a superconducting transition upon small chemical substitutions in them. As it is currently unclear which ‘dopants’ can favor of superconductivity, this manuscript investigates crystal structure changes upon chemical substitutions, to find clues in lattice parameters for the superconducting occurrence. We review the chemical substitution effects on the crystal lattice of iron-based materials (2008 to present). We note that (a) HTS compounds have nearly tetragonal structures with a-lattice parameter close to 4 Å, and (b) superconductivity can depend strongly on the c-lattice parameter changes with chemical substitution. For example, a decrease in c-lattice parameter is required to induce ‘in-plane’ superconductivity. The review of lattice parameter trends in iron-based superconductors presented here, should guide synthesis of new materials and give clues for superconductivity.},
doi = {10.1088/1361-648X/aa4e03},
journal = {Journal of Physics. Condensed Matter},
number = 8,
volume = 29,
place = {United States},
year = {Thu Jan 12 00:00:00 EST 2017},
month = {Thu Jan 12 00:00:00 EST 2017}
}

Journal Article:
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  • The lanthanide coinage-metal diarsenides LnTAs{sub 2} (Ln=La, Ce-Nd, Sm; T=Ag, Au) have been reinvestigated and their structures have been refined from single crystal X-ray data. Two different distortion variants of the HfCuSi{sub 2} type are found: PrAgAs{sub 2}, NdAgAs{sub 2}, SmAgAs{sub 2}, GdAgAs{sub 2}, TbAgAs{sub 2}, NdAuAs{sub 2} and SmAuAs{sub 2} crystallize as twofold superstructures in space group Pmcn with the As atoms of their planar layers forming zigzag chains, whereas LaAgAs{sub 2}, CeAgAs{sub 2} and PrAuAs{sub 2} adopt a fourfold superstructure (space group Pmca) with cis-trans chains of As atoms. The respective atomic positions can be derived from themore » HfCuSi{sub 2} type by group-subgroup relations. The compounds with zigzag chains of As atoms exhibit metallic behaviour while those with cis-trans chains are semiconducting as measured on powder pellets. The majority of the compounds including 4f elements show antiferromagnetic ordering at T{sub N}<20 K. - Text3: Zigzig vs. cis-trans.« less
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