Growth kinetics of anodic oxide films on cobalt silicides in sulfuric and hydrofluoric acids solutions

Abstract

The growth kinetics of anodic oxide layers was studied on cobalt silicides Co2SiandCoSi2in 0,5 mol/l H2SO4 solution with addition of 0,005 or 0,01 mol/l HF using chronoamperometric measurements at different oxide formation potentials. The kinetics of oxide growth can be described on the basis of the high field model. The current responses to potential steps for Co2Si electrode appear as damped oscillations. The oscillating processes were explained from the standpoint of the theory of linear electric circuits and from the consideration of chemical interaction of the oxide film with the solution.