Anomaly in the rate of oxygen absorption by zirconium due to the formation of oxide at the surface: autocatalytic reaction model of oxide nucleation

Abstract

The rate of oxygen absorption by polycrystalline zirconium has been measured at oxygen pressures of 6.7 × 10^–5–1.3 × 10^–3 Pa over the temperature range 743–1073 K. An anomaly in the rate of oxygen absorption has been observed at the stage of nucleation of surface oxide, i.e. the rate of oxygen absorption is increased by the formation of oxide at the surface. The rate of oxygen absorption at the nucleation stage is numerically evaluated by using a model in which nucleation and growth of oxide at the surface is approximated by an autocatalytic reaction.