Electrochemical Epitaxy and XMCD Study of Co-Ni Alloy Film

Using the electrochemical cyclic voltammetry, Co-Ni alloy film was deposited on single-crystal GaAs(001) substrate. With the scanning electron microscopy (SEM) and X-ray fluorescence (XRF), the thickness of the film was about 180 nm and the surface of the alloy was composed of 40 nm-sized Co66Ni34 nanograins. The faced center cubic structure of the alloy was confirmed using X-ray diffraction (XRD). The X-ray magnetic circular dichroism (XMCD) spectra of Co and Ni were obtained from the X-ray absorption spectra (XAS) results using synchrotron radiation circularly polarized soft X-ray. According to the sum rules, the orbital and the spin magnetic moments of Co and Ni were separately obtained. Compared with the pure Co and Ni samples, the orbital and the spin magnetic moments of Co and Ni in the epitaxial Co-Ni alloy showed an increase to some extent.