Polytypism, polymorphism, and superconductivity in TaSe 2 −x Te x

Abstract

Although polymorphs of a substance can often have dramatically different physical properties, polytypes, which occur when the geometry of a structural layer is maintained but the number of layers in the layer-stacking sequence is changed, rarely do. Here we find, using random substitution of Te for some of the Se to induce structural changes in TaSe 2 , a classic layered dichalcogenide, so that the transition temperature to superconductivity ( T c ) is significantly different for different polytypes and polymorphs and especially differs when going from one polytype to another. This observation implies either a surprising sensitivity of T c to the layer-stacking sequence or a similarly surprising sensitivity of T c to the small changes in layer geometry that accompany the change in polytype.

Document Details

Document Type
Pub Defense Publication
Publication Date
Mar 03, 2015
Source ID
10.1073/pnas.1502460112

Entities

People

  • Ali Yazdani
  • Andras Gyenis
  • Hiroyuki Inoue
  • Huixia Luo
  • Jason W. Krizan
  • Jing Tao
  • Robert Cava
  • Weiwei Xie
  • Yimei Zhu

Organizations

  • Army Research Office
  • Brookhaven National Laboratory
  • Division of Materials Research
  • Princeton University
  • United States Department of Energy
  • Yusuf Hamied Department of Chemistry

Tags

Fields of Study

  • Physics

Readers

  • Electrochemical Surface Science
  • Semiconductor Device Technology
  • Theoretical Analysis.