Optical, magnetic, and transport behaviors of Ge1−xMnxTe ferromagnetic semiconductors grown by molecular-beam epitaxy

Abstract

The optical, magnetic, and transport behaviors of Ge1−xMnxTe (x=0.24 and 0.55) grown by solid-source molecular-beam epitaxy are investigated. X-ray diffraction shows that Ge1−xMnxTe crystallizes in rocksalt structure. The temperature-dependent magnetization (M-T) for x=0.55 sample gives a Curie paramagnetic temperature of θp∼180 K, which is consistent with the temperature-dependent resistivity ρ(T) measurement. Anomalous Hall effect is clearly observed in the samples and can be attributed to extrinsic skew scattering based on the scaling relationship of ρxy∝ρxx1.06. The magnetoresistance of Ge1−xMnxTe is isotropic and displays a clear hysterestic loop at low temperature, which resembles that of giant-magnetoresistance granular system in solids.