Study of the grain size, particle size and roughness of substrate in relation to the magnetic properties of electroplated permalloy

In this work, the substrate grain size effect on the deposition of Ni₇₉Fe₂₁ film by electroplating has been studied. The morphology, surface roughness, particle size and magnetic properties of the deposited films are investigated in detail. The investigation shows that the grain size of the deposited films scales with the increase of the substrate grain size. It has shown that the surface roughness of the substrate is of importance. The smoother the substrate surface, the smaller the surface roughness and material coercivity of the deposited Ni₇₉Fe₂₁ film. This study indicates that the smoothness and uniformity of the substrate surface are important parameters to be taken into account during electroplating. Under such consideration, Ni₈₁Fe₁₉/Cu composite wire has been deposited by sputtering a layer of Cu on the Cu substrate surface to improve Cu wire surface smoothness and uniformity. It is found that with the sputtered Cu layer, the GMI effect of the deposited Ni₈₁Fe₁₉/Cu composite wire has been significantly increased.