The study of defects in Ga0.946Mn0.054As by X-ray absorption spectra

Abstract

The influence of the major compensating defects As antisites (AsGa) and Mn interstitials (MnI) in the Ga0.946Mn0.054As diluted magnetic semiconductor (DMS) were studied by X-ray absorption spectra (XAS). The experimental results show that the defects in Ga0.946Mn0.054As grown at lower temperature (TS=200℃) is mainly AsGa, but at TS>230℃ MnI is the major defects. On the other hand, a higher LT-annealing temperature (250℃) can remove MnI out of the Ga0.946Mn0.054As lattice, and the highest Curie temperature (TC=130 K) is reached. Moreover, it is indicated that the LT-annealing process can increase the number of MnGa atoms by reducing the concentration of AsGa defects and driving MnI defects to fill up the holes left by AsGa.