MAGNETIC AND MAGNETOOPTICAL PROPERTIES OF COBALT-PLATINUM ALLOYS WITH PERPENDICULAR MAGNETIC-ANISOTROPY

Co1-xPtx alloys with Pt contents in the range 0.45 less-than-or-equal-to x less-than-or equal-to 0.9 show sizable perpendicular magnetic anisotropy, 100% perpendicular remanence and coercivities in the range 160 kA/m. Thin films of this material are grown by electron beam evaporation onto fused silica or Si, at substrate temperatures between 150 and 350-degrees-C. Spectroscopic investigations of the polar Kerr rotation show a significant enhancement of the Pt related UV peak. A comparison of the static signal levels R X (theta(k)2 + epsilon(k)2)1/2 of Co/Pt multilayers and alloys shows an overall 50% enhancement in the case of alloys. Curie temperatures around 200-degrees-C are observed for Co(approximately 22)Pt(approximately 78) compositions. These properties, together with the potentially high chemical stability and ease of manufacturing make Co1-xPtx alloys very attractive materials for short wavelength magneto-optic recording.