Effect of Heating Rate on Soft Magnetic Properties in Nanocrystalline Fe80.5Cu1.5Si4B14 and Fe82Cu1Nb1Si4B12 Alloys

The effect of the heating rate in the annealing process of rapidly quenched Fe80.5Cu1.5Si4B14 and Fe82Cu1Nb1Si4B12 amorphous alloys on their soft magnetic properties is investigated. The iron loss in magnetic flux density region of B > 1.55T in Fe80.5Cu1.5Si4B14 alloy decreases by high-heating-rate annealing (HA). The coercivity H-c and the saturation magnetic flux density B-s in HA specimen of Fe82Cu1Nb1Si4B12 alloy were about 3 A/m and 1.78T. By applying HA to high-Fe-concentration amorphous alloys such as Fe82Cu1Nb1Si4B12, Fe82Cu1Nb1Si2B12P2, and Fe80.8Cu1.2Si5B11P2, the nanocrystalline alloys with a high B-s of more than 1.75T and a low H-c of about 3 A/m are obtained. (C) 2009 The Japan Society of Applied Physics