Time effects in the electrodeposition of CoPt magnetic alloys

Electroplating of magnetic alloys is often the preferred method of fabrication of micropermanent magnets for microelectromechanical system applications. Electroplated cobalt-platinum alloys have the desired magnetic characteristics. However, the observed current efficiency, the composition, and the magnetic properties of the deposit change with the amount of charge passed. This impedes the manufacturability of alloys. These changes are undoubtedly associated with changes in the composition of the bath, specifically the nature of the Pt-containing complex. Here we discuss the possible changes in the [Pt (NH3) 2 (NO2) 2] 0 complex and in the other components of the bath, employing the methods of voltammetry.