Spin-wave excitations and magnetism of sputtered Fe/Au multilayers

The spin-wave excitations and the magnetism of Fe/Au multilayers with different Fe thicknesses (tFe) grown by RF sputtering were investigated. The temperature dependence of spontaneous magnetization is well described by a T3/2 law in all multilayers in the temperature range of 5–300 K. Spin-wave theory has been used to explain the temperature dependence of the spontaneous magnetization and the approximate values for the exchange interactions for various tFe were obtained. The spin-wave constant B was found to increase linearly with the inverse in the Fe thickness (1/tFe). Using the ferromagnetic resonance technique, the change of the anisotropy field HK as a function of 1/tFe was deduced. The spatial distributions of the discrete spin-wave modes were calculated. All the extracted results were in agreement with those determined experimentally and found in the literature.