Electrotransport of Interstitial H and D in V, Nb, and Ta as Experimental Evidence for the Direct Field Force

Steady-state electrotransport measurements were performed for H and D interstitials in V, Nb, and Ta. The measurements were made in the temperature range between 49\ifmmode^\circ\else\textdegree\fi{}C and 245\ifmmode^\circ\else\textdegree\fi{}C and with hydrogen concentrations up to an atom ratio of 0.054. The results yield strong experimental evidence for the existence of a direct field force.