Pulse plating of soft high magnetic moment materials - Properties and application

In this paper, we present recent results obtained for pulse plating of 1.8 T CoNiFe alloy. As a starting point, a comprehensive model is developed that explains and mathematically describes the phenomenon of pole tip depression observed in the case of direct current deposition. Based on this model and its results the parameters like pulse time, rest time, and magnitude of the pulse current j(pp) are defined so the optimal conditions for pulse plating are achieved. The duration of the pulse stage is correlated to a parameter we refer to as the transition time, by taking pulse time to be less than or equal to transition time. The rest time was defined as the time when no current is passing thorough the electrode-electrolyte interface and concentration profile on the interface is recovered to an arbitrary portion of the value existing before the current pulse was applied. Using such a defined pulse function, high moment and low coercivity CoNiFe magnetic alloys were obtained and we were able to achieve uniform deposition in the features down to a 50 nm size.