ELECTRODEPOSITION OF CoAg FILMS FROM EMIC IONIC LIQUID

Abstract

CoAg films were prepared by ionic liquid electrodeposition to replace conventional aqueous electrodeposition on a copper substrate. Effects of different EMIC concentrations on composition, microstructure and magnetic properties of CoAg films were investigated. With the increase of 1-Ethyl-3-methylimidazolium Chloride (EMIC) concentration, atomic percentage of cobalt in CoAg films increased dramatically but amounts of silver reduced gradually. Almost all of the deposited films were crystalline and contained fcc- Ag(200) and hcp- Co(002) diffraction peaks. With the increase in EMIC concentration, the intensity of Co(002) peaks increased, which led to better crystalline and larger grain size. Dissimilar surface morphology of CoAg films from different EMIC concentration systems could be detected. CoAg films with bigger grain size and rougher surface could be obtained when higher concentration of EMIC was introduced during the electrodeposition. Especially, CoAg films with rice-like structures could be observed when EMIC was 0.45 mol/L. With the increase of EMIC concentration, coercivity of CoAg increased gradually from 140 Oe to 260 Oe.