High frequency behavior of magnetic composites based on FeSiBCuNb particles for power electronics

Summary form only given. Nanocrystalline flakes composites (NFC) have been elaborated. The particles are obtained by grinding Fe/sub 73.5/Si/sub 15.5/B/sub 7/Cu/sub 1/Nb/sub 3/ ribbons using turbula or automatic steel mortar. The magnetic particles are mixed with epoxy resin. Magnetic properties of NFC cores are improved by mechanical orientation of the particles during the cold pressing. The mixture is polymerized at 80/spl deg/C. Then, toroidal samples are machine-finished for the magnetic measurements at an induction level up to 70 mT. Permeability can be adjusted from 20 to 60 by modifying the volume-charging rate, which depends on the particle sizes and the compacting pressure. The /spl mu//sub rs//spl times/f/sub r/ product (initial static permeability /spl times/ relaxation frequency) of NFC cores varies between 7 and 12 GHz.