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Title: Probing the local environment of two-dimensional ordered vacancy structures in Ga{sub 2}SeTe{sub 2} via aberration-corrected electron microscopy

There has been considerable interest in chalcogenide alloys with high concentrations of native vacancies that lead to properties desirable for thermoelectric and phase-change materials. Recently, vacancy ordering has been identified as the mechanism for metal-insulator transitions observed in GeSb{sub 2}Te{sub 4} and an unexpectedly low thermal conductivity in Ga{sub 2}Te{sub 3}. Here, we report the direct observation of vacancy ordering in Ga{sub 2}SeTe{sub 2} utilizing aberration-corrected electron microscopy. Images reveal a cation-anion dumbbell inversion associated with the accommodation of vacancy ordering across the entire crystal. The result is a striking example of the interplay between native defects and local structure.
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [1] ;  [2]
  1. Department of Nuclear Engineering, University of California, Berkeley, California 94720 (United States)
  2. (United States)
  3. National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
  4. Department of Materials Science and Engineering, University of California, Berkeley, California 94720 (United States)
  5. Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
Publication Date:
OSTI Identifier:
22283273
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 5; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANIONS; ANTIMONIDES; CATIONS; CONCENTRATION RATIO; CRYSTALS; ELECTRON MICROSCOPY; GALLIUM TELLURIDES; GERMANIUM COMPOUNDS; PHASE CHANGE MATERIALS; SELENIDES; THERMAL CONDUCTIVITY; TWO-DIMENSIONAL CALCULATIONS; VACANCIES