MAGNETIC-ANISOTROPY OF NI AL MULTILAYERS

The magnetic anisotropy of Ni/Al multilayers has been investigated by vibrating sample magnetometer (VSM) and ferromagnetic resonance (FMR) techniques. The FMR spectra are obtained as a function of the orientat ion of the applied magnetic field from in-plane to out-of-plane, and a re fitted theoretically to determine the magnetic anisotropy. From VSM and FMR, a positive value for Ni/Al interface anisotropy, favoring a perpendicular easy axis, is obtained. Furthermore, for the ultrathin m agnetic layer below a critical Ni thickness of 20 Angstrom, a perpendi cular easy axis of magnetization can be extrapolated.