MAGNETISM IN RARE-EARTH TRANSITION-METAL SYSTEMS - MAGNETIZATION REVERSAL AND ULTRA-HIGH SUSCEPTIBILITY IN SANDWICHED THIN-FILMS BASED ON RARE-EARTH AND COBALT ALLOYS

This paper is composed of two parts: theoretical and experimental. The theoretical part is divided into several sections. The main character istic properties of 3d (transition metals) and 4f (rare-earth metals) magnetism are explained in the second section. The properties of rare- earth-transition metal compounds are discussed in the third section, p articularly with respect to applications. The fourth section is devote d to the rapidly growing field of magnetic thin films. Specific proper ties of ultra-thin films and multilayers are summarized. In the experi mental part the original magnetic properties of sandwich films, consis ting of a soft amorphous Co-Zr layer placed between two Sm-Co layers w ith different coercivities, are reported.