Effets des additifs organiques sur les propriétés de films minces granulaires de Co-Cu

Abstract

In this work, we investigate the effect of organics additives on the electrochemical characteristics, morphological, structural and magnetic properties of thin films of Co-Cu granular system, obtained by electrodeposition on n-Si and FTO substrate from a sulfate bath. From the voltammetric study, the kinetic study of the deposits is optimized. Analysis of the transient currents using the theoretical model of Scharifker-Hills indicates that the nucleation mechanism of the alloy Cu-Co follows an instantaneous nucleation mechanism followed by diffusion limited growth. This mode may change if specific additives are added to the bath. The charactérization of the samples was determined ex-situ by atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and alternating magnetic field gradient magnetometers (AGFM). The surface morphology of the films changes with the nature of additive. X-ray diffraction indicates that the films crystallize in varieties of phases; a mixture of Co fcc and hcp, and Cu fcc structures are obtained. The magnetization of these alloys is pronounced for all additives. Globally, films exhibiting such properties are suitable for magnetic applications.