MAGNETISM OF RARE-EARTH TRANSITION-METAL NANOSCALE MULTILAYERS .2. THEORETICAL-ANALYSIS OF MAGNETIZATION AND PERPENDICULAR MAGNETIC-ANISOTROPY

Systematic studies of rare-earth transition-metal amorphous compositionally modulated films (CMF) permit the development of a detailed model for understanding the magnetization and perpendicular magnetic anisotropy and their distributions along the film normal. It is shown that the single-ion anisotropy of rare-earth ions with orbital angular momentum is the major contributor to the perpendicular anisotropy for this class of CMF. The calculated results agree well with the experimental data for Dy/Co and Tb/Fe CMF when the individual layer thicknesses are small enough (<10); these films have structures which can be characterized as compositionally modulated amorphous alloys. © 1990 The American Physical Society.