Magnetic properties of HITPERM (Fe,Co)(88)Zr7B4Cu1 magnets

A new class of nanocrystalline alloys with composition Fe44Co44Zr7B4Cu1 has been developed. This and similar alloys of general composition (Fe, Co)-M- B-Cu (where M=Zr, Hf, Nb, etc.) have been named HITPERM. They offer large m agnetic inductions and excellent soft magnetic properties at elevated tempe ratures. Thermomagnetic properties, permeability, and frequency dependent l osses are described in this report. These alloys exhibit high magnetization that persists to the alpha --> gamma phase transformation at 980 degrees C . Alternating current permeability experiments reveal a high permeability a t 2 kHz with a loss value of 1 W/g at B-s = 10 kG and f = 10 kHz. (C) 1999 American Institute of Physics. [S0021-8979(99)52908-3].