H diffusion in the H-storage TiVMnCr alloys as deduced from absorption and mechanical spectroscopy experiments

'Me low H content portion of the PCT absorption curves of the 40Ti-xV-(50-x)Mn-10Cr alloys exhibits a plateau, whose pressure has been determined together with the solubility limit of H in the alpha-phase (solid solution). The chemical (D-c) and Einstein (DE) diffusion coefficients of H have been deduced from H absorption kinetics (273 K- I 100 K) and from mechanical spectroscopy (150 K-200 K), which has revealed a Snoek-type of anelastic relaxation. The combined Affhenius plot of DE and Dc gives the following parameters for H diffusion: W=0.318 +/- 0.005 eV, D-0=(41)X 10(-7) m(2)/S (36 V alloy) and W=0.352 +/- 0.005 eV, D-0=(51)10(-7) m(2)/s (32 V alloy).