The effect of annealing and frequency of the external magnetic field on magnetic properties of nanostructured electrodeposit of the Ni86,0Fe9,8W1,3Cu2,9 alloy

Abstract

A nanostructured powder of the Ni86,0Fe9,8W1,3Cu2,9 alloy is deposited on a titanium cathode by electrodeposition from the citrate bath, at the current density of 400 mA cm−2. The powder particles are of a cauliflower and dendritic shape and composed of nanocrystals of the FCC phase of the solid solution of iron, tungsten and copper in nickel, captive in an amorphous matrix. The freshly deposited powder is thermally stable up to 160 °C. The annealing of the powder in the temperature range from 160 °C to 460 °C results in its structure relaxation. At temperatures higher than 460 °C, the amorphous phase in the powder is crystalizing and crystal grains of the FCC solid solution are growing. The structural changes caused by annealing, affect magnetic properties of the alloy. The cooled powders after the structure relaxation have higher magnetization, a lower loss of the active power and a lower coercive field. Crystallization of the amorphous phase and crystalline grain growth of the FCC phase causes a decrease in magnetization, an increase in the power loss and the power of coercive field.