Crystallographic and magnetic behavior in crystallization process of FeTaC film

We have studied the crystallographic and magnetic behavior of amorphous Fe₇₉Ta₁₀C₁₁ films during the crystallization process. The crystallization process starts with the precipitation of Ta or TaC_1-x. The saturation magnetizations of the film and Fe grain size increase at the same time. The increase in saturation magnetization is completed at ~480°C, Fe and Ta phase separation seem to be completed at this temperature. The anomalous state appears between 480 and 530°C, in which good soft magnetic properties do not appear at room temperature, although the Fe grain size is small enough. The source of this phenomenon is the weak intergranular ferromagnetic coupling caused by the formation of a magnetic material with a low Curie point at the Fe grain boundary