Magnetoresistance Probe of Ultrathin Mn5Ge3 Films with Anderson Weak Localization

We present the magnetoresistance measurements of ultrathin Mn5Ge3 films with different thicknesses at low temperatures. Owing to the lattice mismatch between Mn5Ge3 and Ge (111), the thickness of Mn5Ge3 films has a significant effect on the magnetoresistance. When the thickness of Mn is more than 72 monolayers (MLs), the magnetoresistance of the Mn5Ge3 films appears a peak at about 6kOe, which shows that the magnetoresistance results from the Anderson weak localization effect and the variable range hopping in the presence of a magnetic field. The magnetic and semiconducting properties indicate that the Mn5Ge3 film is a potential material for spin injection. (condensed matter: electronic structure, electrical, magnetic, and optical properties)