Optimization of half-Heusler PtMnSb alloy films for spintronic device applications

摘要

Half-Heusler PtMnSb alloy films were optimized with varying deposition temperatures on Cr/Ag-buffered MgO(001) substrates by investigating structural and magnetic properties. Epitaxial growth was achieved in PtMnSb films grown at 200 degrees C while high magnetization of 530 emu cm(-3) was observed at 500 degrees C. Compared to other Heusler alloys, the PtMnSb films show relatively large anisotropic magnetoresistance ratios with negative sign, which could be attributed to high spin-orbit interaction in the PtMnSb films owing to Pt. Furthermore, current-perpendicular-to-plane giant magnetoresistance (CPP-GMR) devices as a kind of representative spintronic devices were fabricated with the structure of PtMnSb/Ag/PtMnSb. Room-temperature CPP-GMR effect was first observed in the PtMnSb-based CPP-GMR devices.