Abstract
The magnetization and Curie temperature of sputter-deposited MnZn ferrite thin films are examined. As-deposited films at room temperature and 300°C are crystalline and have a spinel structure. However, their saturation magnetization is smaller and their Curie temperatures are higher than those of heat-treated films at 800°C-900°C. The results are explained by assuming that the ion distribution in the as-deposited films is in nonequilibrium: Some of the Zn ions and Mn ions occupying the A sites in equilibrium occupy the B sites, and the same number of Fe ions transfer to the A sites. Moreover, in the films heat-treated at 800°C-900°C, the saturation magnetization decreases and the Curie temperature rises with a rise in the heat treatment temperature. These are also explained on the basis of a variation in the equilibrium ion distribution with the heat treatment temperature.
