Spin-Wave Excitations in Evaporated Co/Pt Multilayers

The magnetic properties of evaporated Co/Pt multilayers have been studied by magnetic measurements and ferromagnetic resonance (FMR). The spin-wave resonances were observed in some multilayers in FMR experiments, which implied that spin waves were sustained by the whole and propagated through Pt layers. The relation of the resonance field H (res) with the mode number n obeys the so-called n (2) law and the interlayer coupling strength J (I) has been determined. The temperature dependence of the spontaneous magnetization can be well described by Bloch's law, in all multilayers. The increase of the spin-wave parameter B with decreasing cobalt thickness has been discussed. A spin-wave theory has been used to explain the temperature dependence of the magnetization and the approximate values for the bulk exchange interaction J (b) and surface exchange interaction J (S) for various Co/Pt multilayers have been obtained.