Magnetic studies of Fe/Pt multilayers

The magnetization and anisotropy of Fe/Pt multilayers prepared by RF sputte ring are presented. The samples with individual Fe thickness of 2.5 Angstro m show a dependence of magnetisation on Pt thickness. We found that as the Pt layer became thick enough (>18 Angstrom) to magnetically isolate the Fe layers, a quasi-linear temperature dependence of the magnetisation results due to the 20 spin-wave excitations. As the Pt layer is reduced, a dimensio nal crossover in the excitations is induced by the magnetic interaction bet ween Fe layers which makes M(T) change from quasi-linear behaviour to more bulk-like behaviour. Magneto-optical polar Kerr effect spectra between 1.5 and 5.7 eV measured on a series of magnetic multilayers Fe/Pt with a varied thickness of ultrathin Fe are reported. (C) 2000 Elsevier Science B.V. All rights reserved.