Magnetooptical Spectra in Pt-Ni Alloys and Multilayers

Pt-Fe, Pt-Co and Pt-NiCo alloys and multilayer films were prepared on a SiO2 substrate by the dc magnetron sputtering technique. The reflectivity spectra and magnetooptical Kerr spectra of these specimens were measured, and the diagonal and off-diagonal elements of the conductivity tensor were deduced. The results of this work are as follows: (1) The peak energy position of the magnetooptical Kerr rotation spectra showed a systematic shift to lower energies as the transition metal was changed from Fe to Ni, both in multilayer and alloy samples. (2) Simulation using the above-determined conductivity tensor for alloys revealed that alloy layers exist at the interfaces between Pt and the transition metal in all the Pt-based multilayer films investigated. (3) Obvious effects of plasma enhancement were confirmed in the short-wavelength magnetooptical Kerr spectra of the Pt-based alloys.