The potential dependence of Co–Cu alloy thin films electrodeposited on n-Si(100) substrate

Abstract

The aim of this work is to study the effect of the deposition potential on the properties of Co–Cu alloy thin films on n-type Si substrate. Voltammetric measurements showed that the potential dissolution of Co and consequently the composition of the films depend greatly on the applied potentials. The compositional measurement, which was made using an atomic absorption spectroscopy (AAS), demonstrated that the Co content of the films considerably increases as the applied potentials tend toward negative values. SEM micrographs revealed a transition of branched dendritic structures to well covered, agglomerated and compact alloy morphology with increased Co concentrations in the deposits. X-ray diffraction analysis showed that the films crystallize in varieties of phases; a mixture of Co fcc and hcp, and Cu fcc structures, greatly related to applied potential. The increase of the applied potential induces a decrease in the grain size and the lattice constant. The magnetization of the alloys was found to be enhanced for high Co concentrations and consequently at high deposition potential.