Post-annealing effect on the electronic structure of Mn atoms in Ga(₁-x)Mn(x)As probed by resonant inelastic x-ray scattering.

The electronic structure of as-grown and post-annealed Ga(₁-x)Mn(x)As epilayers (x≈0.055) has been investigated using resonant inelastic x-ray scattering. Mn L₂,₃ x-ray emission spectra show that the integral intensity ratio of Mn L₂ to L₃ emission lines increases with annealing temperature and comes close to that of manganese oxide. The oxygen K-emission/absorption spectra of post-annealed Ga₀.₉₄₅Mn₀.₀₅₅As show 1.5-3.0 times higher degree of oxidation on the film surface than that of the as-grown sample. These experimental findings are attributed to the diffusion of Mn impurity atoms from interstitial positions in the GaAs host lattice to the surface where they are passivated by oxygen.