Effective Valence of Tritium in the Alpha Phase of Niobium

The effective valence Z* of tritium and protium dissolved in niobium was measured by a steady-state electromigration experiment in a temperature region from 379 K to 521 K. A new experimental technique using an isotope mixture of tritium and protium was adopted to discriminate a comparatively small mass dependence of effective valence. The trend Z*(T)>Z*(H) of isotope dependence was confirmed.