Microelectrodeposition of cobalt and cobalt alloys for magnetic layers

Structure and growth characteristics of electrodeposited cobalt are discussed with regard to its electrokinetic behaviour. Three main growth modes are pointed out: outgrowth or perpendicular growth, in conditions of low surface inhibition; lateral growth, with complete coverage of the electrode by hydrolytic species giving a high degree of surface inhibition; cluster growth, in the presence of surface complex species stabilised by boric acid. The structure influence upon the magnetic properties is discussed with reference to the electrodeposition of thick layers of Co–Pt–W alloys, with Pt and W content, respectively in the range 8–15 and 1–5 at.%, having high coercivity and high magnetic moment.