Annealing effect on magnetic and electronic properties of polycrystalline Ge1−xMnx semiconductors grown by MBE

MBE-grown poly Ge1−xMnx/SiO2/(100)Si semiconductor thin films were annealed, and magnetic properties of the annealed semiconductors have been studied. As-grown poly Ge1−xMnx semiconductor has p-type carriers and electrical resistivity is in the range of 4.0×10−3–0.5×10−3Ωcm at room temperature. The carrier type is not changed during annealing, but the electrical resistivity increases with annealing temperature and time. During annealing Ge3Mn5 ferromagnetic phase transforms into Ge8Mn11 anti-ferromagnetic phase and then the Ge8Mn11 phase is decomposed into Ge, β-Mn and some unidentified phases.