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Title: Ferro-Lattice-Distortions and Charge Fluctuations in Superconducting LaO 1- x F x BiS 2

Abstract

Competing ferroelectric and charge density wave states have been proposed to exist in the electron–phonon coupled LaO1-xFxBiS2 superconductor. The lattice instability is proposed to arise from unstable phonon modes that can break the crystal symmetry. Using single crystal diffraction, a superlattice pattern is observed, that arises from coherent in-plane displacements of the sulfur atoms in the BiS2 superconducting planes. The distortions morph into coordinated ferrodistortive patterns with displacements in the x- and y-directions, that alternate along the c-axis. Diffuse scattering is observed along the (H0L) plane due to stacking faults but not along the (HH0) plane. The ferro-distortive pattern remains in the superconducting state upon fluorine doping, but the displacements are diminished in magnitude. Moreover, we find that the in-plane distortions give rise to disorder where the (00L) reflections become quite broad. It is possible that charge carriers can get trapped in the lattice deformations reducing the effective number of carriers available for pairing.

Authors:
 [1];  [2];  [3];  [3];  [3];  [4];  [5];  [1]
  1. Department of Physics, University of Virginia, Charlottesville, VA 22904, U.S.A.
  2. Oak Ridge National Laboratory, Oak Ridge, TN 37831, U.S.A.
  3. Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506, U.S.A.
  4. Hefei High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, China
  5. Argonne National Laboratory, Lemont, IL 60439, U.S.A.
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science - Office of Basic Energy Sciences - Scientific User Facilities Division; National Science Foundation (NSF)
OSTI Identifier:
1392439
DOE Contract Number:
AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of the Physical Society of Japan; Journal Volume: 86; Journal Issue: 5
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY

Citation Formats

Athauda, Anushika, Hoffmann, Christina, Aswartham, Saicharan, Terzic, Jasminka, Cao, Gang, Zhu, Xiangde, Ren, Yang, and Louca, Despina. Ferro-Lattice-Distortions and Charge Fluctuations in Superconducting LaO 1- x F x BiS 2. United States: N. p., 2017. Web. doi:10.7566/JPSJ.86.054701.
Athauda, Anushika, Hoffmann, Christina, Aswartham, Saicharan, Terzic, Jasminka, Cao, Gang, Zhu, Xiangde, Ren, Yang, & Louca, Despina. Ferro-Lattice-Distortions and Charge Fluctuations in Superconducting LaO 1- x F x BiS 2. United States. doi:10.7566/JPSJ.86.054701.
Athauda, Anushika, Hoffmann, Christina, Aswartham, Saicharan, Terzic, Jasminka, Cao, Gang, Zhu, Xiangde, Ren, Yang, and Louca, Despina. 2017. "Ferro-Lattice-Distortions and Charge Fluctuations in Superconducting LaO 1- x F x BiS 2". United States. doi:10.7566/JPSJ.86.054701.
@article{osti_1392439,
title = {Ferro-Lattice-Distortions and Charge Fluctuations in Superconducting LaO 1- x F x BiS 2},
author = {Athauda, Anushika and Hoffmann, Christina and Aswartham, Saicharan and Terzic, Jasminka and Cao, Gang and Zhu, Xiangde and Ren, Yang and Louca, Despina},
abstractNote = {Competing ferroelectric and charge density wave states have been proposed to exist in the electron–phonon coupled LaO1-xFxBiS2 superconductor. The lattice instability is proposed to arise from unstable phonon modes that can break the crystal symmetry. Using single crystal diffraction, a superlattice pattern is observed, that arises from coherent in-plane displacements of the sulfur atoms in the BiS2 superconducting planes. The distortions morph into coordinated ferrodistortive patterns with displacements in the x- and y-directions, that alternate along the c-axis. Diffuse scattering is observed along the (H0L) plane due to stacking faults but not along the (HH0) plane. The ferro-distortive pattern remains in the superconducting state upon fluorine doping, but the displacements are diminished in magnitude. Moreover, we find that the in-plane distortions give rise to disorder where the (00L) reflections become quite broad. It is possible that charge carriers can get trapped in the lattice deformations reducing the effective number of carriers available for pairing.},
doi = {10.7566/JPSJ.86.054701},
journal = {Journal of the Physical Society of Japan},
number = 5,
volume = 86,
place = {United States},
year = 2017,
month = 5
}
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