Fucheng Yu

The Effects of Codoping of Be and Mg on Incorporation of Mn in GaAs

)Abstract Samples of GaMnAs, GaMnAs codoped with Be, and GaMnAs simultaneously codoped with Be andMg were grown via low-temperature molecular beam epitaxy (LT-MBE). Be codoping is shown to take the Gasites into the lattice efficiently and to increase the conductivity of GaMnAs. Additionally, it shifts thesemiconducting behavior of GaMnAs to metallic while the Mn concentration in the GaMnAs solid solution isreduced. However, with simultaneous codoping of GaMnAs with Be and Mg, the Mn concentration increasesdramatically several times over that in a GaMnAs sample alone. Mg and Be are shown to eject Mn from theGa sites to form MnAs and MnGa precipitates.Key wordsGaMnAs, Be codoping, Mg codoping, MBE, Magnetic semiconductor PACS: 75.50Pp, 75.70Ak, 81.15.Hi