ABSTRACT Antimony is finding use in semiconductor technology for making infrared detectors, thin film capacitors,1 and photoanodes.2 It greatly increases the hardness and mechanical strength of lead and so it is used as an alloying additive in lead alloys for grids in lead-acid batteries.3 The corrosion processes at open-circuit conditions were investigated in acid solutions by Laitinen, et al.4 The authors found that Sb dissolution at opencircuit conditions is coupled to oxygen reduction via the hydrogen peroxide (H2O2) route. At open-circuit conditions, Sb is covered with an oxide film formed by a field-controlled process.5 Anodic polarization increases the electric field across the film and leads to film growth by ionic conductivity.5 The potential of an Sb electrode is a corrosion potential and it is therefore of primary interest to know the nature of the different reactions that might occur at its surface. Studies of the chemistry of Sb emphasize mainly the formation of barrier-insulating oxide films in a range of electrolytes.5-9 Many investigators have focused their attention on the stability and the dissolution reactions of these oxide films. There is agreement that the anodic oxide films electroformed on the Sb electrode under potentiodynamic or galvanostatic conditions consist of an inner porous antimony oxide (Sb2O3) layer and an outer antimony pentoxide (Sb2O5) layer. The experimental findings showed that the nature and stability of the antimony oxide film are functions of different parameters like formation medium, dissolution medium, formation voltage, formation current density, and temperature.8-9 In a recent work, Pavlov, et al., used an ellipsometric technique to investigate the nature and stability of oxide films formed on Sb electrodes.10 The authors found that potentiodynamic oxidation of Sb takes place within two potential regions. They also observed a break in the chronopotentiometric (E-t) curves in the 3-to-4-voltage range during galvanostatic anodic oxide growth. The authors attributed these findings to anodic growth of