Magneto-optical spectra of long range chemically ordered FePd(001) alloy films

The occurrence of chemical ordering can have a dramatic influence on structural, electronic, and magnetic properties in many materials systems. Examples of recent interest are binary metallic alloy systems such as CoPt, FePt, and FeAu, where strong interdependencies between magnetic and magneto-optical properties and the degree of long range chemical ordering have been observed. Near the equiatomic composition, these ordered alloys form a CuAu (L10) crystal structure, i.e., a face centered lattice with pure Cu and Au planes stacked along the @001# direction. Such natural superlattice phases exhibit strong tetragonal distortions along the @001# axis often accompanied by large magnetic anisotropies and enhanced magneto-optical effects, as it was shown most evidently for FePt. It was further shown, that these ordered metallic alloys can be obtained employing thin film growth techniques at temperatures well below the bulk disorder–order transition temperature. This together with relatively large magnetic anisotropies make them potential candidates for future ultrahigh density magnetic recording disk applications. In this article, we discuss magnetic and magneto-optical properties of FePd. This is another but less explored example of an ordered phase with the CuAu (L10) crystal structure. 11