Magnetic properties of amorphous ferrromagnetic Co2MnSi/Pt multilayers

Ferrromagnetic Co2MnSi (CMS)/Pt multilayer with perpendicular magnetic anisotropy (PMA) is investigated. A series of amorphous CMS/Pt multilayers with various interface numbers are fabricated by sputtering method. PMA is found to be strongly related to the individual thickness of the CMS/Pt bilayer and the repetition number. For the intermediate Pt spacer thicker than 1.2 nm PMA is demonstrated in the multilayers with CMS thickness in the range of 0.3∼0.7 nm. The effective perpendicular anisotropy energy is measured to be in the order of 102 kJ/m3 in magnitude. The interfacial anisotropy energy density is determined to be 0.58 mJ/m2 per interface. With increasing repetition number wasp-waist shaped magnetization hysteresis appears, showing the switching mechanism with multi-domain feature. Our findings provide some useful information to explore CMS/Pt multilayer-based structures with large PMA for next-generation spintronic devices.