Buffer-Layer Dependence of Interface Magnetic Anisotropy in Co2Fe0.4Mn0.6Si Heusler Alloy Ultrathin Films.

Buffer-layer dependences of dead-layer thickness, saturation magnetization ( M\mathrm {s}) , and interface magnetic anisotropy ( K\mathrm {s}) were systematically investigated for Co2Fe0.4Mn0.6Si (CFMS) Heusler alloy ultrathin films with Pd, Ru, and Cr buffer layers. Perpendicular magnetization was only achieved in 0.6 and 0.8 nm-thick CFMS ultrathin films deposited on Pd buffer layer and annealed at 400 °C. At the optimum annealing temperature of 400 °C, K\mathrm {{s}} of 1.2 erg/cm2 was obtained for the Pd buffer layer, which was 3–6 times larger than those for Ru and Cr buffer layers. The difference in K\mathrm {{s}} probably originates from the interdiffusion and different crystallized compounds at the interface between Pd (Ru, Cr) and CFMS layers. [ABSTRACT FROM AUTHOR]