B. Bandyopadhyay et S. Hayashi, Sites and dynamics of hydrogen in TI0.1V0.9HxDy (x+y approximate to 0.7) as studied by H-1 nuclear magnetic resonance, J ALLOY COM, 305(1-2), 2000, pp. 136-143
Ti0.1V0.9HxDy (x + y approximate to 0.7) alloys have been studied by means
of X-ray powder diffraction, differential scanning calorimetry (DSC) and H-
1 nuclear magnetic resonance (NMR). The crystal structures of the H-rich sa
mples and the samples of [H]/[D]=1 are body-centered-tetragonal (bct) at ro
om temperature, while those of the D-rich samples are body-centered-cubic (
bcc). A phase transition similar to that from the delta(D) phase to the alp
ha(D) phase is observed around 200-220 K in all the samples except for the
hydride. In the hydride, Ii atoms occupy the octahedral (O) sites. In the I
I-rich samples, H atoms occupy both the O and tetrahedral (T) sites. In the
sample of [H]/[D]=1 and the D-rich sample, H atoms occupy the T sites. The
temperature and frequency dependence of H-1 spin-lattice relaxation times
(T-1) has been analyzed by modified Bloembergen-Purcell-Pound (BPP) equatio
ns. The activation energy of Ii diffusion is higher in the O sites than in
the T sites. D addition to the hydride and Ti addition decrease the activat
ion energy in the O sites. The H diffusion in the T sites is not affected b
y the Ti addition or by the [H]/[D] ratio. (C) 2000 Elsevier Science S.A. A
ll rights reserved.