ABSTRACT

Owing to their exceptional magnetic properties, the Co-Ni alloy thin films are used as magnetic recording media and as hard magnetic materials for microelectromechanical systems (MEMS) applications. In our research, we will study the effect of saccharin additive in the bath on the structural and magnetic properties of Co-Ni alloy. In order to investigate this effect, different analytical techniques had been used through atomic force microscopy (AFM),   X-ray diffraction and hysteresis curves. The conditions of electrodeposition of Co–Ni alloys were determined using the cyclic voltametry (clearly show the presences of cathodic peaks that correspond to deposition are observed around 1.20 V). From AFM when saccharin concentration increased from 0 to 0.005 M, the RMS roughness decreases from 88 down to 14 nm. From XRD the average size of crystallites decreases with increasing saccharin additive concentration in the chloride baths. It can be suggested that adsorption of saccharin molecules can block the active growth centers during electrodeposition and acts as a grain refiner. Effectively, the presence of the saccharin in the bath also causes notable changes in. Indeed, because of the presence of saccharin the deposits exhibit lower values of coercivity and magnetization saturation compared to those without saccharin. The coercivity values decrease to 1.4 Oe and magnetization saturation decreases in comparison to the film without saccharin, although the decrease in Ms is considerably lower at the highest saccharin content of 0.00 M. The magnetic properties of the deposits can be related to the grain refinement and the internal stress.

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