Novel Fe-based nanocrystalline powder cores with excellent magnetic properties produced using gas-atomized powder

[Display omitted] •(Fe0.76Si0.09B0.1P0.05)98.5Nb1Cu0.5 nanocrystalline powder cores are fabricated by gas-atomized powders as raw material.•Nanocrystalline powder cores can effectually reduce the load/no-load audible noise.•Nanocrystalline powder cores exhibit higher permeability and lower core loss.•The optimum nanocrystalized temperature is 480 °C for 0.5 h in vacuum. FeSiBPNbCu nanocrystalline powder cores (NPCs) with excellent magnetic properties were fabricated by cold-compaction of the gas-atomized amorphous powder. Upon annealing at the optimum temperature, the NPCs showed excellent magnetic properties, including high initial permeability of 88, high frequency stability up to 1 MHz with a constant value of 85, low core loss of 265 mW/cm3 at 100 kHz for Bm = 0.05 T, and superior DC-bias permeability of 60% at a bias field of 100 Oe. The excellent magnetic properties of the present NPCs could be attributed to the ultrafine α-Fe(Si) phase precipitated in the amorphous matrix and the use of gas-atomized powder coated with a uniform insulation layer.