The effect of annealing temperatures on magnetic and electric properties of electrodeposited Ni85,3Fe10,6W1,4Cu2,2 alloy

Abstract

Ni-85,Ni-8 Fe-10,Fe-6 W-1,W-4 Cu-2,Cu-2 alloy powder consisting of an amorphous matrix and nanocrystals of an FCC solid solution of Fe, W and Cu in nickel was produced by electrodeposition. Heating the pressed powder sample over the temperature range of 20 to 600 degrees C permitted structural changes to take place in the alloy, causing changes in its electrical resistivity and magnetic permeability. The alloy exhibits structural stability up to 150 degrees C. In the temperature interval 150-360 degrees C, the alloy undergoes intensive structural relaxation resulting in an increase in electrical conductivity and magnetic permeability. Less intensive structural relaxation occurs at temperatures between 360 degrees C and 460 degrees C. In this interval, under heat treatment, magnetic domain arrangement decreases and, hence, the interaction between magnons and conduction electrons is reduced, leading to a decrease in the temperature coefficient of electrical resistivity (TCER). Amorphous matrix crystallization and FCC crystal growth take place in the temperature interval 460-520 degrees C, causing a decline in electrical resistivity and magnetic permeability.