Multilayer films (MLFs) composed of FePt ordered alloy and Pt were prepared by an ion beam sputtering method. The FePt layer thickness (dFePt) was varied in the range from 1 to 10 nm, keeping the Pt layer thickness to 5 nm. The torque and magnetization measurements revealed that all the FePt/Pt MLFs grown on MgO(100) substrates were perpendicularly magnetized films except for the case of dFePt around 5 nm, where a structural anomaly leading to the absence of the multilayer periodicity was seen. The main origin of the perpendicular magnetic anisotropy is considered to be the magnetocrystalline anisotropy of the FePt layers. When the total thickness was decreased to 19 nm, a φK remanence ratio of about 100% was obtained.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics