MBE Growth and Transport Properties of MnGeP2 under Various P Pressure

We have studied the magneto-transport properties of ferromagnetic MnGeP2 semiconductor thin films deposited on GaAs(100) by using molecular beam epitaxy (MBE) under diverse beam equivalent pressures (BEP) of phosphorus. The growth direction was along the c-axis of the film, whose surface was very rough. The temperature-dependent electrical resistance results strongly support the presence of a ferromagnetic phase transition in the chalcopyrite MnGeP2 thin film around 320 K. On the other hand, it shows all anisotropic magneto-resistance and an anomalous Hall effect in p-type MnGeP2 thin films, indicating the presence of spin-polarized hole carriers in MnGeP2. We have successfully observed magnetic domains at room temperature by using magnetic force microscopy (MFM).