Anwendung elektrochemischer Verfahren zur Untersuchung der Diffusion von Wasserstoff-Isotopen in V, Nb und Ta / Application of Electrochemical Techniques for Studying Diffusion of Hydrogen Isotopes in V, Nb and Ta

Abstract

After suitable preparation (improvement) of samples H (D) -diffusion coefficients of V-, Nb-, and Ta-foils can be measured reliably at low H (D) -concentrations in the temperature range 0 to 100 °C by means of an electrochemical time-lag method. A modified strain model indicates that the tetrahedral sites in bcc lattices have to be taken as the stable positions for the dissolved hydrogen. The elementary jump in the diffusion process from one tetrahedral site to the next passes directly through a tetrahedral plane. This model describes qualitatively the experimental results concerning the sequence of the activation energies for hydrogen diffusion in the three Vb-metals [E(Ta)>E(Nb)>E(V)].