Compositional and Structural Analysis of FeCo Films Electrodeposited at Different Temperatures

In this paper, the effect of electrodepositing temperature on the composition and microstructure of FeCo films were investigated in details. At low temperature (less than 40 °C) Fe is preferentially deposited. With increasing temperature, the Co content is increased while Fe content is decreased. The film grown at RT has a mixed phase (fcc + bcc), but the films deposited at 30 °C and 40 °C show only bcc phase. When the electrodeposition temperature is increased to 50 °C, a metastable α-Mn phase becomes dominant and bcc phase is relatively less in the Fe Co film. Further increasing the temperature to 60 °C, the film has a mixed phase of α-Mn phase and hcp Co phase. It can be concluded that elevated electrodeposition temperature promotes the formation of metastable α-Mn phase while the fcc solid solution forms at low temperature. The bcc α-Co7Fe3 phase is favored at intermediated temperature. FeCo films with mixed phases have a finer grain size than that of the films with single phase due to the competitive growth of grains in the mixed phase.