Si effects on a thermal stability and a crystallization behavior of P-riched Fe(-Si)-B-P-Cu alloys

Nanocrystalline soft magnetic ribbons with high saturation magnetic flux density Bs and low coercivity Hc are attracted for high power devices. Ribbon-shaped samples with compositions of Fe83.3B16-xPxCu0.7 (x=4-10) were prepared. The activation energy of the crystallization reaction was estimated by Kissinger’s plot. The value of the Hc after the crystallization reaction was measured. As a result, it was found that as the amount of phosphorus increases, the activation energy of the crystallization reaction increases and the Hc decreases, but ΔTx become smaller. Finally, it turned out that silicon substitution is effective for stabilizing the Hc after heat treatment.