Magnetic and magneto-optic properties of (Nd, Pr)Gd/FeCo multilayers

Abstract

Magnetic and magneto-optic (MO) properties are investigated for (Nd,Pr)Gd/FeCo multilayer films (MLFs) prepared by means of rf magnetron sputtering. Perpendicularly magnetized films with a good square Kerr hysteresis loop, which is necessary for high density magnetic recording media, are prepared by adjusting the composition as well as the thickness of each layer and bilayer period. Within the frame of this work, the best result is obtained for conditions of approximately 33% Nd, approximately 10% Co, bilayer period of 1 nm, and bilayer thickness ratio of 1. The figure of merit for the Kerr read out in MO memory is found to be 0.36 deg at 400 nm, which is about 30% larger than that for Tb-FeCo.