An effect of a thickness of rapidly-quenched ribbon and of insulating coating on soft magnetic properties of nanocrystalline cores

The nanocrystalline cores made from rapidly-quenched amorphous ribbons are increasingly used in power electronics, particularly in high-frequency and high-temperature applications. Under this work, the influence of ribbon thickness and of an emulsion coating applied between ribbon coils on soft magnetic properties of nanocrystalline toroidal cores made from this ribbon was investigated. The amorphous ribbons of different thickness were cast by rapid-quenching from the FeCuNbSiB and FeCoNbBP alloys and next toroidal cores were wound from them. The cores were prepared with and without the use of an emulsion insulation and subjected to thermo-magnetic treatment conducted under protective atmosphere of argon. Next, soft magnetic properties of the cores were measured within a frequency range from 50 Hz to 300 kHz. It was found that the ribbon thickness and the use of ribbon coating influence soft magnetic properties of both studied alloys.