Preparation of new amorphous powder cores using Fe-based glassy alloy

So as to obtain a new metallic powder core with constant permeability and low core loss up to higher frequency range, we have tried to prepare the amorphous alloy powder cores by using the Fe/sub 70/Al/sub 5/Ga/sub 2/P/sub 9.65/C/sub 5.75/B/sub 4.6/Si/sub 3/ glassy alloy powders that have a wide supercooled liquid region (/spl Delta/T/sub x/) below the crystallization temperature (T/sub x/). The Fe-based glassy alloy powder core (FGAPC) had a constant permeability of about 110 up to 10 MHz, which is comparable to commercial cores. The FGAPC also had a lowest core loss of 610 kW/m/sup 3/ at B/sub m/=0.1 T and f=100 kHz in any other metallic powder cores. These excellent magnetic properties of the FGAPC in a higher frequency range are presumably due to an extremely low coercive force (H/sub c/) derived from sufficient elimination of internal stress by annealing at near the /spl Delta/T/sub x/ and its higher electrical resistivity (/spl rho/) of about 1.60 /spl mu//spl Omega/m for the Fe/sub 70/Al/sub 5/Ga/sub 2/P/sub 9.65/C/sub 5.75/B/sub 4.6/Si/sub 3/ glassy alloy. These excellent magnetic properties of the FGAPC, therefore, allows us to expect that this core will be suitable for high frequency drive magnetic devices such as a choke coil, reactor and so on.