The influence of transition metal solutes on the dissolution and diffusion of oxygen in tungsten

Abstract

First-principles calculations are applied to perform a systematic study on the interaction between transition metal (TM) solutes and oxygen in tungsten. The interactions between all considered TM solutes and oxygen are attractive, which can be understood by the combination of the elastic and electronic interactions. Based on the results of the solute-oxygen interaction, the influences of TM solutes on the oxygen dissolution and diffusion are estimated. We found that Mo, Re and Os show weak influences on oxygen while Ti, V, Cr, Zr, and Hf significantly increase oxygen solubility and reduce oxygen diffusivity. Furthermore, we explored the synergistic effect among TM solutes, vacancy and oxygen. The early TM solutes can enhance the oxygen trapping effect of the vacancy, while late TM solutes show little effects on vacancy-oxygen interaction. Meanwhile, the oxygen can increase the stability of the solute-vacancy pairs especially for the case of Ti and V. Our calculation results are in agreement with recent experimental results, and provide the necessary input parameters for subsequent multiscale studies on the atomic processes involved in oxidation.