Compositional dependencies of ferromagnetic Ge_(1-x)Mn_xTe grown by solid-source molecular-beam epitaxy

摘要

The IV-VI diluted magnetic semiconductor Ge_(1-x)Mn_xTe thin films on BaF_2 (111) substrate have been prepared using solid-source molecular-beam epitaxy technique by varying the Mn concentrations from x=0.25 to 0.98. The chemical Mn concentration was determined by x-ray photoelectron spectroscopy measurement. The in situ reflection high-energy electron diffraction pattern indicates that the growth mechanism is in the island-growth mode. The x-ray diffraction shows that the Ge_(1-x)Mn_xTe films crystallize in the NaCl phase with (111) orientation. A clear ferromagnetic ordering is observed in the detailed temperature-dependent magnetization measurement for 0.25