Structure evolution of Fe-based nanocrystalline soft magnetic powder cores with excellent properties

The effect of heat treatment temperature on the structural evolution and soft magnetic properties of FeSiBNbCu soft magnetic powder cores (SMPCs) was systematically investigated. The comprehensive magnetic properties of the SMPCs first increased and then decreased with an increase in temperature. At 600 °C, the SMPCs grain size was approximately 8.8 nm, presenting a concentrated nanocrystalline structure, and showing the best soft magnetic properties, including low core loss of 135.6 mW/cm3 (50 mT, 100 kHz), stable effective permeability of 49.1 up to 10 MHz and high DC bias performance of 60.3% at 100 Oe. This study provides an effective solution for the preparation of Fe-based nanocrystalline SMPCs with excellent performance and validates the application prospects under working conditions of different frequencies and ripple currents.