Local lattice distortions and dynamics in extremely overdoped superconducting YSr2Cu2.75Mo0.25O7.54

Research output: Contribution to journalArticleScientificpeer-review

Researchers

  • Steven D. Conradson
  • Theodore H. Geballe
  • Andrea Gauzzi
  • Maarit Karppinen
  • Changqing Jin
  • Gianguido Baldinozzi
  • Wenmin Li
  • Lipeng Cao
  • Edmondo Gilioli
  • Jack M. Jiang
  • Matthew Latimer
  • Oliver Mueller
  • Venera Nasretdinova

Research units

  • J. Stefan Institute
  • Washington State University Pullman
  • Stanford University
  • CNRS
  • Chinese Academy of Sciences
  • University of Chinese Academy of Sciences
  • Université Paris-Saclay
  • CNR
  • Center of Excellence on Nanoscience and Nanotechnology - Nanocenter
  • United States Department of Energy

Abstract

A common characteristic of many “overdoped” cuprates prepared with high-pressure oxygen is Tc values ≥ 50 K that often exceed that of optimally doped parent compounds, despite O stoichiometries that place the materials at the edge or outside of the conventional boundary between superconducting and normal Fermi liquid states. X-ray absorption fine-structure (XAFS) measurements at 52 K on samples of high-pressure oxygen (HPO) YSr2Cu2.75Mo0.25O7.54, Tc = 84 K show that the Mo is in the (VI) valence in an unusually undistorted octahedral geometry with predominantly Mo neighbors that is consistent with its assigned substitution for Cu in the chain sites of the structure. Perturbations of the Cu environments are minimal, although the Cu X-ray absorption near-edge structure (XANES) differs from that in other cuprates. The primary deviation from the crystal structure is therefore nanophase separation into Mo- and Cu-enriched domains. There are, however, indications that the dynamical attributes of the structure are altered relative to YBa2Cu3O7, including a shift of the Cu-apical O two-site distribution from the chain to the plane Cu sites. Another effect that would influence Tc is the possibility of multiple bands at the Fermi surface caused by the presence of the second phase and the lowering of the Fermi level.

Details

Original languageEnglish
Pages (from-to)4559-4564
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume117
Issue number9
Publication statusPublished - 3 Mar 2020
MoE publication typeA1 Journal article-refereed

    Research areas

  • Cuprates, High-pressure oxygen, Local structure, Overdoped

ID: 41812993