Breakdown voltage and electronic current studies of aluminium-aluminium oxide-electrolyte systems

Abstract

Breakdown voltages and electronic current data (at constant voltage) of anodic aluminium oxide films in contact with different aqueous electrolytes of varying concentrations and compositions have been obtained at 298K. Both breakdown voltage and electronic current depend on electrolyte concentration, resistivity and composition. A linear relation between breakdown voltage and logarithm of electronic current has been observed. The effect of electrolyte concentration, composition and resistivity on breakdown voltage has been discussed in terms of Ikonopisov electron injecting avalanche model of electrical breakdown [<em>Electrochim Acta, </em>22 (1977) 1077]. The major factor contributing to the decrease in breakdown voltage with increasing electrolyte concentration is the increasing primary electronic current. Breakdown voltage decreases with increase in temperature. Addition of ferrous ions to the electrolyte decreases the breakdown voltage, the effect being pronounced at higher concentrations.