Dependence of Soft Magnetic Properties of Alloys on P Content

Effects of P content in amorphous and nanocrystalline FeSiBPCu soft magnetic alloys were investigated by comparing the corresponding change in the saturation magnetic flux density and coercivity. Ribbons were prepared using a high induction melting and melt spinning method. As-quenched Fe_85.5Si₂B₁₀P_1.5Cu₁ alloy consisted of minor crystalline phase. With an increase of P content, the glass forming ability was enhanced. The decrease in the saturation magnetic flux density associated with increased P content, was mainly ascribed to the decrease in Fe content. Nanocrystalline Fe_87-xSi₂B₁₀P_xCu₁ alloys exhibited higher saturation magnetic flux density and lower coercivity, when x was >2 at%. The best soft magnetic performance was obtained at x = 2 at%, where the saturation magnetic flux density was 1.87 T. The coercivity was decreased with P content, indicating that the size of α-Fe grains became smaller with the increase of P content.