Saturation magnetization in ferromagnetic thin films

The present status of the theory of saturation magnetization of ferromagnetic thin films is reviewed. The extensions of the Heisenberg trace method and the spin-wave method to the case of ferromagnetic thin films is fully discussed together with a comparison of the theoretical results with experimental data. The effect of anisotropic magnetic fields on magnetization and Curie temperature is presented, and the dependence of the magnetization and Curie temperature on film thickness is studied. Very recent progress and new results of the theory are stressed. The application of the Green function method to ferromagnetic thin films is also examined.