Effect of P to B concentration ratio on soft magnetic properties in FeSiBPCu nanocrystalline alloys

The effects of P to B concentration ratio on magnetic properties and microstructure in annealed Fe 82.65 Si 2 B 14− x P x Cu 1.35 ( x =1−6) soft magnetic alloys prepared by melt spinning were investigated. The proper substitution of B with P was found to be effective in decreasing grain size in the alloys annealed at 793 K for 120 s. The coercive force H c markedly decreases from 67.1 to 1.1 A/m and the saturation magnetic flux density B s shows a slightly decreasing trend with increasing P content from x =1 to 5. The nanocrystalline Fe 82.65 Si 2 B 9 P 5 Cu 1.35 alloy, with an average grain size of 15 nm, shows a combination of high B s and excellent soft magnetic properties.