DFT Calculations to Study Hydrogen Localization and Diffusion in Disordered Bcc Ti-V-Cr Alloys

摘要

Here we report on the results of our theoretical study of hydrogen localization and motion in disordered bcc Ti-V-Cr alloys. The calculations have been carried out within a DFT supercell approach for a certain composition, namely Ti_(0.33)V_(0.27)Cr_(0.4) for H/M = 1/32. It was found that hydrogen is localized in highly distorted tetrahedral sites formed by different metal species. H atoms are displaced towards titanium. The estimation of the hydrogen diffusion parameters provides the activation energy value of 0.126 eV and the diffusion coefficient at 294 K equal to 1.9 × 10-~(10) m/s~2 that is in good agreement with available experimental data.