Effect of chloride ions on remanence variation in two-step-annealed electroplated Fe–Pt films

Abstract In our previous studies, a variation in remanence was observed in electroplated Fe–Pt films subjected to a two-step annealing process, consisting of low-temperature annealing followed by high-temperature annealing. This phenomenon was suggested to be related to structural changes in the Cu substrate during low temperature annealing. In the present study, we investigate the effect of chloride ions in the electroplating bath on the magnetic properties of two-step annealed Fe–Pt films. In contrast to previous results obtained without Cl- ions, no significant variation in remanence was observed. X-ray diffraction analysis of the Cu substrate region revealed that annealing-induced changes in the Cu diffraction peaks during LT-A at 300°C were suppressed for films prepared from the chloride-containing bath. The present findings provide an effective guideline for controlling the magnetic properties of electroplated Fe–Pt films by regulating substrate structural stability.