A fabrication process of soft magnetic Ni films electroplated from gel electrolyte

Abstract

We have already reported some electroplated magnetic films using aqueous solutions. In the present study, we proposed a fabrication process for electroplated soft magnetic films (Ni films) using gel electrolytes. We added gelatin to the plating baths and confirmed that adding 22 g/L of gelatin enabled us to obtain gel electrolytes. Using the gel electrolytes, we electroplated Ni films and evaluated their structural and magnetic properties. From the evaluation of magnetic properties, we confirmed spontaneous magnetization of the Ni films prepared from the gel electrolyte. For obtaining thick Ni films (>1 μm), we investigated stirring the gel electrolyte during plating. As a result, we found that stirring increased the thickness, and our result suggests that stirring the gel electrolyte is useful to increase the deposition rate. In our experimental conditions, the deposition rate of the plating process was ∼0.25 μm/min. From XRD analysis, the structure of Ni films for gel electrolytes was oriented in the fcc (220) plane and slightly different from that for liquid electrolytes. From these results, we found that soft magnetic films could be obtained from the gel electrolyte and that gel plating is one of the attractive fabrication processes of the thick films.