High moment FeCoNi alloy thin films fabricated by pulsed-current electrodeposition

Soft, high moment FeCoNi thin films were fabricated by pulsed-current electrodeposition, in which the period with current flow was in the range 0.5-20 s and period with no current flow in the range 0-30 s. Film composition is determined by two concurrent phenomena, anomalous codeposition and diffusion-limited reduction of Fe, whose relative importance can be controlled by adjusting the duration of the current pulses. For short current pulses and long intervals between pulses the anomalous deposition process dominates and the films are Fe-rich. Under these conditions, the ratio of BCC/FCC phases is also higher, which increases the saturation magnetization of the film. For long current pulses and short intervals between pulses the diffusion of Fe²⁺ ions in the electrolyte dominates the reduction reaction. Correspondingly, the films are Ni-rich and the ratio of BCC/FCC phases is reduced