The effective valence Z* of protium and deuterium in the α phase of Ta has been measured by means of a stationary state electromigration experiment in the temperature region from 373 K to 523 K. A definite isotope dependence Z*(H) >Z*(D) has been found. The reversal of the isotope dependence to Z*(H) < Z*(D) in the temperature region below 350 K has been suggested from the temperature dependence of Z*. The direct valence Zd of H and D has been evaluated by relating the temperature dependence of Z* to that of electric resistivity, leading to the values 1.7 and 0.91 respectively. We also found that the contribution of the wind valence Zw is negative and depends on the isotopes.
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry