Properties of electrodeposited Co-Mn films: Influence of deposition parameters

Abstract

Co-Mn films were produced with electrodeposition considering the deposition parameters of electrolyte pH value, Mn concentration of the electrolyte and film thickness. The effect of each parameter on the structural, magnetic and magnetoresistance properties of the films was studied, separately. X-ray diffraction measurement showed that the films have hexagonal close packed structure. For the films deposited at different pH values, the surface morphologies with different-sized globular granules were observed whereas the morphology covered by uniformly distributed nanoscale grains was detected for the surfaces of all films produced from electrolytes with different Mn concentrations. Also, the ribbed surfaces for 6 mu m and 4 mu m, and the nano-sized acicular surface morphologies for 2 mu m were observed. To the results of magnetic measurements, the saturation magnetization was found to be 1230 emu/cm(3) for all films deposited at different electrolyte pHs. The highest remanent magnetization value was obtained to be 882 emu/cm(3) for the film produced from the electrolyte containing 0.06 M Mn concentration. The coercivity, H-c, values decreased from 147 Oe to 43 Oe when the electrolyte pH decreased from 4.7 to 2.6. And, the Hc continued to decrease from 45 Oe to 31 Oe when the Mn concentration increased from 0.02 M to 0.06 M, and from 27 Oe to 22 Oe when the film thickness decreased from 6 pin to 2 mu m. It is seen that the Hc was immensely affected by the deposition parameters applied during the film production. The Co-Mn films with low Hc were achieved using relatively low electrolyte pH, high Mn concentration of electrolyte and low film thickness, respectively. Also, influence of the deposition parameters affect Hc is in order of the electrolyte pH, the Mn concentration in the electrolyte and the film thickness (from high to low influence). As it is observed that the magnetic properties are sensible to the deposition parameters and the Co-Mn films may have the potential applications in magnetic recording and sensors technologies.