Structure and magnetic properties of pulse-plated FeP and FeCuP amorphous alloys

FeP and FeCuP alloys have been prepared by pulsed galvanostatic electrodeposition from a sulphuric acid solution. A current pulse, with a height of 100 mA cm^-2 and on and off time durations of 100 ms, was found to be most effective for the formation of FeP amorphous alloy. The composition range of the plating solution giving an amorphous structure was wider for pulse plating than for direct current plating. Most of the pulse-plated amorphous alloys contained about 20 at.% P and their lowest coercive force (H_c) was about 0.2 Oe. The pulse-plated FeCuP ternary alloy was deposited even at a high pulse current density of 1 A cm^-2. The alloy formed at 300 mA cm^-2 showed the lowest H_c of 0.5 Oe. Cross-sectional scanning electron microscopy examination of the pulse-plated FeCuP alloy revealed a very fine multilayered structure.