Alloy thin films of interest for possible electronic applications were obtained by electrodeposition : Ni-Fe for magnetic heads, Co alloys for magnetic recording and Cu-Sb as a possible underlayer for electric contacts. Permalloy ECD Ni-Fe films were deposited from acid baths on Si wafers, patterned by photolithography; Co-Pt and Co-Pd films from baths of similar composition, obtaining hard Co-Pt and soft Co-Pd layers; Cu-Sb as oversaturated solid solutions or as multilayers depending on the deposition conditions. Electrokinetic behaviour and related structures are interpreted by means of the normality-inertia parameter P(ni).