MAGNETIC-PROPERTIES OF HEISENBERG-TYPE FERROMAGNETIC-FILMS WITH A SANDWICH STRUCTURE

The Greens function method is developed for a sandwich structure in which a type-II ferromagnet is sandwiched between two ferromagnets of type I. The interface interactions are assumed to be ferromagnetic. Magnetization profiles and transition temperatures in such composite systems are derived for several sets of material parameters. It is shown that, if the surface anisotropy is weak, these thermodynamic quantities are affected definitely by the strong-exchange material, while if the surface anisotropy is strong, they are dependent on a competition between the effect of surfaces and the strong-exchange material. The relation to an infinite-multilayer system is also discussed. © 1990 The American Physical Society.