Thermal, structural and soft magnetic properties of FeSiBPCCu alloys

Lower Si and C-content Fe83.3Si2B13-xPxC1Cu0.7 alloys were prepared in order to investigate the influence of P substitution on thermal, structural and soft magnetic properties. Thermodynamic investigation reveals that proper P addition not only favors the amorphous formation but also expands the crystallization window and inactivates the annealing sensitivity of alloys. Microstructure and X-ray photoelectron spectroscopy analysis indicate P addition facilitates homogeneous precipitation of alpha-Fe nanocrystals but results in the formation of loose packing structure, favors the p-d hybridization and promotes the annihilation of effective magnetic moments of Fe atoms, leading to the decrease in saturation magnetic flux density (B-s) of amorphous phase. By proper isothermally annealing, the Fe83.3Si2B9P4C1Cu0.7 nanocrystalline alloy was developed combined with high B-s of 1.78 T, low coercivity of 4.6 A/m, and high permeability of 15100.