Structural magnetotransport and magnetic properties of the electrodeposited Ni Fe films arising from electrolyte pH

Abstract

Ni-Fe films were grown on polycrystalline titanium substrates by electrodeposition. Microstructure, magnetoresistance and magnetic properties of the films were studied as a function of the electrolyte pH. Structural characterizations by X-ray diffraction showed that all films have face centred cubic structure, but the crystal texture degree was different for the films grown at high and low pH levels. At low pH the films have a preferred (111) orientation, at high pH preferred orientation is the (220). The compositional analysis revealed that the Fe content of the films increases as the electrolyte pH decrease. It was found that all films exhibited anisotropic magnetoresistance (AMR). The AMR values of the films grown at high pH are larger compared to the films at low pH. It was observed that the saturation magnetisation increases due to the increase of the Fe content in the films and the coercivities are almost constant. The magnetic easy axis is in the film plane for all samples. The differences observed in the magnetic and magnetotransport properties of the films most probably arise from the structural and compositional changes caused by the electrolyte pH.