Comparison of Ni-Cu alloy films electrodeposited at low and high pH levels

Abstract

Ni-Cu alloy films were potentiostatically electrodeposited from the electrolytes with low pH (2.0) and high pH (3.3) levels. The structural analysis of the films was carried out using the X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The XRD data showed that the crystal texture degree was different for the films grown at high pH and low pH. At high pH, the films have a strong (100) texture of the face-centred cubic (fcc) structure, while for the films at low pH the crystal planes are randomly oriented, as in a powder pattern of Cu (or Ni). The SEM studies revealed that the surface morphology of the films strongly depend on the electrolyte pH. Furthermore, the magnetic characteristics studied by a vibrating sample magnetometer (VSM) and magnetotransport properties were observed to be affected by the electrolyte pH. The differences observed in the magnetic and magnetotransport properties were attributed to the structural changes caused by the electrolyte pH.