The chemical diffusion coefficients of H and D in Ti were determined by performing Gorsky effect measurements at high H and D concentrations. The measurements were performed between 160 and 310C for H(D)/Ti atom ratios ranging from 1.5 to 1.71 (pure face-centered cubic γ-phase). The diffusion coefficients were essentially independent of concentration and obeyed Arrhenius laws with activation energies of 0.520 and 0.530eV for H and D, respectively. The H diffused about 1.5 times faster than D. For a given concentration and isotope (H), the chemical diffusion coefficients in Ti were 10 to 50 times larger than the present or published data on self-diffusion coefficients determined by field-gradient nuclear magnetic resonance and quasi-elastic neutron spectroscopy. These large differences resulted mainly from high values of the concentration derivative of the chemical potential of H in Ti.

M.Hein, A.Bals, A.F.Privalov, H.Wipf: Journal of Alloys and Compounds, 2003, 356-357, 318-21