Electrodeposition of nano-sized nuclei of magnetic Co¯Ni alloys onto n-Si (1 0 0),

Nanometer-sized nuclei of Co¯Ni alloys were electrodeposited onto n-Si (1 0 0) electrodes from buffered solutions of the metallic ions. The energy levels of the interface Si/(Co(II),Ni(II))aq were determined from Mott¯Schottky plots. Electrodeposition of the alloys occurs by an anomalous mechanism and preferential deposition of Co took place at all the Co(II)/Ni(II) ratios investigated. The morphology and magnetic properties of the nuclei were studied by AFM and MFM, respectively. It is showed that nuclei of height <30 nm and low aspect ratio present a single-domain magnetic behaviour. Larger nuclei depict complex magnetic characteristics, with a progressive built-up of multi-domains.