Magnetic Properties of Fe-M-O(M=Zr, Hf) Films with High Resistivity.

The magnetic properties of Fe-M-O (M=Zr, Hf) films with high electrical resistivity prepared by the rf magnetron sputtering technique in an Ar+O2 atmosphere were investigated. In an as-deposited state, low corecivities (Hc) of 30∼100 A/m for Fe-Hf-O and 160∼240 A/m for Fe-Zr-O were obtained in the compositional range of an O/M ratio of 3∼4. After annealing under optimum conditions in an external field of 160 kA/m, the results obtained for Fe54.9Hf11O34.1 and Fe65.3Zr8.9O25.8 were a saturation magnetization (Bs) of 1.2 T, H, of 64 A/m, and p at 100 MHz of 1600; and Bs of 1.3 T, Hc of 73 A/m, and μ at 100 MHz of 1000, respectively. Furthermore, the electrical resistivities of the films were much higher than those of known metallic soft magnetic films.