AN INVESTIGATION OF MAGNETIC-PROPERTIES OF FE73.5CU1NB3SI13.5B9 ALLOYS

The magnetic phase transition of a rapidly quenched Fe73.5Cu1Nb3Si13.5 B9 alloy has been investigated by two different techniques: differenti al scanning calorimetry (DSC), and thermogravimetry analysis (TGA) und er a magnetic field. The DSC measurement showed two distinct exothermi c peaks during the crystallization process and a detectable peak at th e amorphous Curie transition temperature (T(c) = 325-degrees-C). These results were in good agreement with those measured by TGA under a mag netic field. In addition, the TGA measurements showed the Curie phase transition of the nanocrystalline structure at 570-degrees-C. After th e nanocrystalline structure was fully developed, the relationship betw een the core loss at 10 kHz and temperature was established at two dif ferent magnetic induction levels. There was a minimum of the core loss at certain temperatures, which decreased with increasing magnetic ind uction.