MBE growth and magnetotransport studies of ferromagnetic Ga1−xMnxSb semiconductor layers on hybrid ZnTe/GaAs substrates

Narrow-gap Ga1−xMnxSb layers grown on hybrid ZnTe/GaAs substrates are observed to be ferromagnetic by SQUID magnetization and anomalous Hall effect measurements. The layers display an easy axis of magnetization perpendicular to the layer plane, in contrast to in-plane easy axis orientation observed in Ga1−xMnxSb grown on GaSb substrates. Resistivity measured in the Ga1−xMnxSb/ZnTe/GaAs system shows a well-defined maximum at temperatures close to the ferromagnetic/paramagnetic transition. We determined the spontaneous resistivity anisotropy in Ga0.98Mn0.02Sb grown on hybrid ZnTe/GaAs substrates and compared it to that observed on Ga0.98Mn0.02Sb grown on a GaSb buffer. These results should provide a valuable test for future theories of transport in ferromagnetic semiconductors.