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Title: The role of stoichiometric vacancy periodicity in pressure-induced amorphization of the Ga{sub 2}SeTe{sub 2} semiconductor alloy

We observe that pressure-induced amorphization of Ga{sub 2}SeTe{sub 2} (a III-VI semiconductor) is directly influenced by the periodicity of its intrinsic defect structures. Specimens with periodic and semi-periodic two-dimensional vacancy structures become amorphous around 10–11 GPa in contrast to those with aperiodic structures, which amorphize around 7–8 GPa. The result is an instance of altering material phase-change properties via rearrangement of stoichiometric vacancies as opposed to adjusting their concentrations. Based on our experimental findings, we posit that periodic two-dimensional vacancy structures in Ga{sub 2}SeTe{sub 2} provide an energetically preferred crystal lattice that is less prone to collapse under applied pressure. This is corroborated through first-principles electronic structure calculations, which demonstrate that the energy stability of III-VI structures under hydrostatic pressure is highly dependent on the configuration of intrinsic vacancies.
Authors:
 [1] ;  [2] ; ;  [3] ;  [4] ;  [5] ;  [6] ;  [1] ;  [2]
  1. Department of Nuclear Engineering, University of California, Berkeley, California 94720 (United States)
  2. (United States)
  3. Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
  4. Department of Nuclear Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States)
  5. Department of Materials Science and Engineering, University of California, Berkeley, California 94720 (United States)
  6. Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
Publication Date:
OSTI Identifier:
22314483
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; 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; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AMORPHOUS STATE; CRYSTAL LATTICES; GALLIUM COMPOUNDS; PERIODICITY; SELENIUM COMPOUNDS; SEMICONDUCTOR MATERIALS; STOICHIOMETRY; TELLURIUM COMPOUNDS; VACANCIES