The electrical resistivity of TaHx specimens, where x ranged from 0.025 to 0.27, was studied after preparation via the cathodic charging of 3N-purity Ta. From these results, the activation energy for H self-diffusion was calculated to be 4.17kcal/mol.

Electrical Resistivity of Ta-H System. T.Matsuyama, S.Dohi, K.Hirano: Japanese Journal of Applied Physics, 1973, 12[4], 609-10