Magnetic anisotropy of Ni/Cu sputtered multilayers

Ni/Cu multilayers were grown by RF sputtering. The crystal orientation, the thickness of the elemental layers and the interface quality were analysed by X-ray diffraction in the θ–2θ configuration. Magnetic anisotropy was investigated by both a static and a dynamic technique, namely magneto–optical Kerr effect (MOKE) and Brillouin light scattering (BLS). Longitudinal MOKE loops accounted for the in-plane orientation of the magnetization, while polar loops were used to determine the out-of-plane anisotropy fields, showing the existence of a minor second-order contribution in addition to the first-order one. BLS was then exploited to detect thermal excited spin waves through inelastic scattering of light. The out-of-plane anisotropy fields evaluated by this high-frequency dynamic technique compare well with the first-order values obtained by analysis of polar MOKE hysteresis cycles.