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

Abstract

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 magnetic inductions and excellent soft magnetic properties at elevated temperatures. Thermomagnetic properties, permeability, and frequency dependent losses are described in this report. These alloys exhibit high magnetization that persists to the α→γ phase transformation at 980 °C. Alternating current permeability experiments reveal a high permeability at 2 kHz with a loss value of 1 W/g at Bs=10 kG and f=10 kHz.