1H NMR study of hydrogen self-diffusion in ternary Ti–V–Cr alloys

Hydrogen diffusion in metal-hydrogen systems via NMR and DFT

“…4c and Refs. [56,57] and diffusion [58] measurements result in lower activation energy for the Cr-rich hydride, whereas the corresponding Q' 1 parameter is essentially greater as compared with TiV 0.8 Cr 1.2 H 5.29 (221 and 180 K, respectively). This disagreement is not completely understood.…”

“…Fitting the first frequency [58] and relaxation [55,57] measurement and parameters of the p a (T) and p′ a (T) functions.…”

Hydrogen Diffusion on, into and in Magnesium Probed by DFT: A Review

“…To make H 2 dissociate on an Mg surface, an extra portion of energy-the so-called activation energy E act -has to be supplied. The origin of this activation barrier is mainly determined by electronic factors [30][31][32][33], but the hydrogen behavior is also influenced by an oxide film on the metal surface. In practice, to achieve better hydrogen capacity and kinetics before first hydrogenation, an activation is required.…”

“…Hydrogen diffusion coefficient in hcp-Mg has been theoretically calculated in Refs. [30,48,87,104] exhibiting a wide variation in two orders of magnitude. Klyukin et al [30,48] studied hydrogen diffusion in hcp-, bcc-and fcc-MgH x with low (x = 0.0625) and moderate (x = 0.5) hydrogen concentrations.…”

“…Several techniques, such as NMR or QUENS, can probe atomic jump rates in a wide range. For example, NMR provides access to jump rates from 10 −1 to 10 11 s −1 [28], which makes it a powerful tool for studying hydrogen self-diffusion in metals [28][29][30][31]. In addition, in an experiment we survey the statistical ensemble behavior.…”