The role of stoichiometric vacancy periodicity in pressure-induced amorphization of the Ga{sub 2}SeTe{sub 2} semiconductor alloy
- Department of Nuclear Engineering, University of California, Berkeley, California 94720 (United States)
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
- Department of Nuclear Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States)
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720 (United States)
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
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.
- OSTI ID:
- 22314483
- Journal Information:
- Applied Physics Letters, Vol. 105, Issue 5; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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