Interdiffusion during growth of Fe on As-rich GaAs(001) substrates was investigated by real time stress measurements. Compared to Ga-rich GaAs(001), interdiffusion processes were decisively reduced. The optimum growth temperature (characterized by abrupt interfaces, pseudomorphic growth and negligible intermixing) was found to lie below 50C. At higher growth temperatures interdiffusion effects increased and eventually led to the formation of a compact crystalline alloy layer of presumably Fe2 + xGa1 − x, as evidenced by transmission electron microscopy and X-ray diffraction.

Stress and Interdiffusion during Molecular Beam Epitaxy of Fe on As-rich GaAs(001). T.Ashraf, C.Gusenbauer, J.Stangl, G.Hesser, M.Wegscheider, R.Koch: Journal of Physics - Condensed Matter, 2011, 23[4], 042001