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Title: Experimental and theoretical identification of a high-pressure polymorph of Ga{sub 2}S{sub 3} with α-Bi{sub 2}Te{sub 3}-type structure

Since the discovery of α-phase Bi{sub 2}Te{sub 3}, Sb{sub 2}Te{sub 3}, and Bi{sub 2}Se{sub 3} as 3D topological insulators, many experimental and theoretical studies of A{sub 2}B{sub 3}-type chalcogenides have been performed to search for new materials with interesting elastic and electric properties at ambient and extreme conditions. In this study, high-pressure properties of Ga{sub 2}S{sub 3} have been characterized by in situ synchrotron X-ray diffraction (XRD), X-ray absorption near edge structure measurements, and Density-functional theory (DFT) calculations. At ∼16.0 GPa, a phase transition of α′-Ga{sub 2}S{sub 3} (Cc and Z = 4) is observed experimentally to a new polymorph, which is indentified to be the tetradymite-type or α-Bi{sub 2}Te{sub 3}-type crystal structure (R3{sup ¯}m and Z = 3) by laser-annealing XRD experiments and DFT calculations. The isothermal pressure-volume relationship of Ga{sub 2}S{sub 3} is well described by the second-order Birch-Murnaghan equation of state with K{sub 0} = 59(2) GPa and K{sub 0}{sup ′} = 4 (fixed) for the α′-Ga{sub 2}S{sub 3}, and K{sub 0} = 91(3) GPa, and K{sub 0}{sup ′} = 4 (fixed) for the tetradymite-type phase. In addition, band gap of α′-Ga{sub 2}S{sub 3} decreases on compression and the tetradymite-type Ga{sub 2}S{sub 3} exhibits metallization based on DFT calculations. The pressure-induced phase transition accompanying by changes of elastic and electricalmore » properties may give some implications to other chalcogenides under high pressure.« less
Authors:
; ; ;  [1] ; ;  [2] ;  [3]
  1. Key Laboratory of Orogenic Belts and Crustal Evolution, MOE, Peking University and School of Earth and Space Sciences, Peking University, Beijing 100871 (China)
  2. Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Science, Beijing 10049 (China)
  3. Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204 (China)
Publication Date:
OSTI Identifier:
22402656
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 19; 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; ABSORPTION; ANNEALING; ANTIMONY TELLURIDES; BISMUTH SELENIDES; BISMUTH TELLURIDES; CRYSTAL STRUCTURE; DENSITY FUNCTIONAL METHOD; ELECTRICAL PROPERTIES; EQUATIONS OF STATE; GALLIUM SULFIDES; PHASE TRANSFORMATIONS; PRESSURE RANGE GIGA PA; X RADIATION; X-RAY DIFFRACTION