Design and Fabrication of Co2FeSi/Pt Multilayers with Perpendicular Magnetic Anisotropy

A series of multilayers consisting of Co2FeSi (CFS) and Pt are sputtered. Perpendicular magnetic anisotropy (PMA) is demonstrated in the CFS/Pt multilayers with CFS thickness in the range of 0.4 similar to 1.0 nm. The individual thicknesses of Pt spacer and Co2FeSi layer as well as interface numbers are shown to strongly affect PMA. Twostep switching is observed in the multilayers with 8 nm Pt spacer, showing typically decoupled feature. The effective perpendicular anisotropy energy is determined to be in the order of 10(6) erg/cm(3). The interfacial perpendicular anisotropy energy density is estimated to be 0.32 erg/cm(2). The magnetic reversal with multi domain feature is observed with increasing interface number. Sufficiently large saturation magnetization is derived from the multilayers with various repetitions. The thickness of magnetic dead layer is found to increase with the number of interface, which may be ascribed to more interdiffusion occurring at the multi-interfaces. Our results provide some useful information for the design and development of spintronic devices based on CFS/Pt multilayers.