抄録
Magnetization dynamics and damping for FePd films were investigated using the all-optical time-resolved magneto-optical Kerr effect. We deposited 16-nm-thick FePd thin films on a single crystal MgO(001) substrate. Both in-plane magnetic anisotropy and perpendicular magnetic anisotropy (PMA) FePd films were fabricated using the magnetron sputtering method at various substrate temperatures Ts. The dependencies of magnetization dynamics on the external magnetic field angle at fixed external magnetic field strengths were analyzed. The effective damping constant, αeff, for FePd films with PMA exhibited anisotropy, whereas the αeff for FePd with in-plane magnetic anisotropy did not depend significantly on the field angle. A uniaxial crystalline magnetic anisotropy constant, Ku1, of 11 Merg/cm3 and a minimum for αeff of 0.007 were observed for film prepared at Ts = 200°C. This αeff value was much smaller than that for other Fe- and Co-based materials with large PMA such as L10-FePt alloy, Co/Pt(Pd) multilayers.
