Interface Magnetic Anisotropy of Pd/Co₂Fe_xMn_1−xSi/MgO Layered Structures

Abstract

Interface magnetic anisotropy of Co₂Fe_xMn_1−xSi Heusler alloy thin films were studied quantitatively. Films of Co₂MnSi (x = 1, CMS), Co₂Fe_0.5Mn_0.5Si (x = 0.5, CFMS), and Co₂FeSi (x = 1, CFS) were fabricated onto MgO (001) substrates with an epitaxially grown Pd (001) under layer, and were capped by an MgO layer. The maximum thickness for the perpendicular magnetization was 0.8 nm for CMS and CFMS, and it was 0.6 nm for CFS. The interface anisotropy energies (K_s) were 1.5, 1.5, and 1.2 erg/cm² for CMS, CFMS, and CFS, respectively. The difference in K_s probably originated from the different alloying conditions at the bottom interface between Pd and Co₂Fe_xMn_1−xSi layers.