Synchrotron EXAFS and XRD studies of Ti–V–Cr hydrogen absorbing alloy

Abstract We reported extended X-ray absorption fine structure (EXAFS) measurements at the Ti, V and Cr K-absorption edges in a Ti–V–Cr alloy before and after hydrogen charging. The results indicated that all the bond lengths increased significantly after hydrogenation, and Ti atoms interacted strongly with V, while V and Cr atoms interacted weakly. The Ti and V atom's coordination numbers in hydrogenated alloy decreased obviously in comparison with the pre-hydrogenation situation. X-ray diffraction (XRD) patterns demonstrated that the structure of Ti–V–Cr alloy had transformed from BCC to FCC during hydrogenation. In addition, we investigated the nanoparticle size distribution in the as-cast and hydrogenated Ti–V–Cr alloy by small-angle X-ray scattering (SAXS) technique.