How much room for BiGa heteroantisites in GaAs1− x Bi x ?
2011; American Institute of Physics; Volume: 99; Issue: 14 Linguagem: Inglês
10.1063/1.3647635
ISSN1520-8842
AutoresG. Ciatto, Paola Alippi, A. Amore Bonapasta, T. Tiedje,
Tópico(s)Machine Learning in Materials Science
ResumoWe addressed the issue of bismuth heteroantisite defects (BiGa) in GaAs1−xBix/GaAs epilayers by coupling x-ray absorption spectroscopy at the bismuth edge with density functional theory calculations of the defect structure. Calculations predict a large relaxation of the Bi-As interatomic distances when Bi atoms substitute Ga, however we found no experimental evidence of it. Quantitative analysis of the x-ray absorption spectra allows us to establish a maximum concentration limit for BiGa, which corresponds to about 5% of the total Bi atoms. BiGa do not account for the modifications in the spectra previously attributed to short range ordering.
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