Contribution of the crystalline phase Fe100-xSix to the temperature dependence of magnetic properties of FINEMET-type alloys

The temperature dependence of the hysteresis loop, saturation magnetization , and saturation magnetostriction of rapidly quenched ribbons of the compos itions Fe100-xSix(x = 12.1, 13,8, 20.0) and of FINEMET-type material with c ompositions Fe73.5Cu1Si13.5B9 and Fe73.5CU1Nb3Si16.5B6 were measured betwee n room temperature and 400 degrees C. This paper analyzes the temperature d ependence of the saturation magnetostriction and the saturation magnetizati on of the FINEMET ribbons after various heat treatments, assuming a superpo sition of the properties of the nanocrystalline Fe-Si and of the remaining amorphous phase. The behavior of the coercivity of Fe-Si prepared by rapid solidification follows roughly that of the (absolute value) of the magnetos triction. The Curie temperature of the remaining amorphous phase is enhance d.