The role of stoichiometric vacancy periodicity in pressure-induced amorphization of the Ga2SeTe2 semiconductor alloy
APPLIED PHYSICS LETTERS, cilt.105, sa.5, 2014 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 105 Sayı: 5
- Basım Tarihi: 2014
- Doi Numarası: 10.1063/1.4892549
- Dergi Adı: APPLIED PHYSICS LETTERS
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Hacettepe Üniversitesi Adresli: Hayır
Özet
We observe that pressure-induced amorphization of Ga2SeTe2 (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 Ga2SeTe2 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. (C) 2014 AIP Publishing LLC.