Angular Dependent Magnetoresistance Measurments in Manganese Telluride Thin Films

Antiferromagnets (AFM) have drawn interests for use in spintronic devices due to their fast dynamics and stability against external fields. Manganese telluride (MnTe) exhibits a Néel Temperature of 307 K and shows a similar magnetic structure to the well-studied α-Fe2O3. In this work we report angular dependent spin-hall magnetoresistance (SMR) measurements of α-MnTe/Pt bilayers. X-ray diffraction scans show high crystalline quality for α-MnTe films of thicknesses from 15 to 60nm on InP(111) substrates. Atomic Force Microscopy reveals the appearance of triangular plateaus in MnTe epitaxial films which suggests good in-plane lattice matching. SQUID magnetometry shows the emergence of a net moment in these antiferromagnetic films, which may influence the SMR in these bilayers. We observe unexpected behavior in angular dependent magnetoresistance signals for all thicknesses of MnTe films. A positive SMR signal is a characteristic of ferromagnets and differs from the negative SMR signal found in α-Fe2O3/Pt bilayers. We explain the unexpected characteristics in the SMR signal and the potential mechanisms underlying this behavior.