Fabrication of FeSiBPCNbCu nanocrystalline soft magnetic powders with high saturation magnetization and low core loss

In this work, with the aim of developing nanocrystalline powder cores (NPCs) with high saturation magnetization (M_s) and excellent magnetic performances, the structure, crystallization behavior and soft magnetic properties of gas-atomized Fe_74.75Si₈B₁₀P_5-xC_xNb_1.5Cu_0.75 (x = 0–3 at.%) powders were investigated. The as-atomized x = 0–2 powders with mean size of 21 μm possess an amorphous structure and the rise of C content from 0 to 2 at.% increases their M_s from 142.2 to 150.9 emu/g. The effects of annealing on magnetic performances of Fe_74.75Si₈B₁₀P₃C₂Nb_1.5Cu_0.75 powders and NPCs were further studied. The powders in the NPCs annealed at 783 K for 60 min possess excellent soft magnetic properties with a high M_s of 158.0 emu/g and low coercivity of 1.5 Oe. The NPCs show excellent magnetic properties including a low core loss of 107 mW/cm³ (50 mT, 100 kHz), high effect permeability (at 100 kHz) of 51.5 and good DC-bias characteristics of 52% at an applied field of 100 Oe. The excellent magnetic performances entitle the developed NPCs great potentials in high-performance electromagnetic applications.