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.