Magnetization and Curie Temperature of As-deposited NiZn Ferrite Thin Films by Sputtering and Changes in Them by Heat Treatment

Abstract

The magnetization and the Curie temperature of NiZn ferrite thin films deposited by sputtering are examined. As-deposited films at room temperature and 300°C are crystalline and have a spinel structure, however, theirsaturation magnetization is small and Curie temperatures are high compared to those of heat-treated films at 400-800°C. The results are explained by an assumption that the ion distribution in the as-deposited films is in a nonequilibrium state, which means a part of Zn ions occupies the B sites and the same number of Fe ions in the B sites transfers to the A sites in the spinel structure.