A new effect is reported in which unexpectedly large voltages are produced by electrochemical cells containing sulfides at natural isotopic abundance levels. Room temperature experiments were undertaken to determine whether electrochemical cells employing silver bromide and silver beta alumina as solid electrolytes would be sufficiently sensitive to detect small variations in sulfur isotopic composition for zinc and lead sulfides. Voltages obtained for silver bromide cells tended to increase progressively over at least 20 days, and increased in a regular fashion with increasing differences in isotopic composition between charges. Voltages exceeding 150 mV were obtained for δS34 differences up to 85 per mil for zinc sulfide, but reached only about 20 mV for lead sulfide. Silver beta alumina cells with opposing zinc and lead sulfide charges yielded larger voltages and an E.M.F. minimum corresponding to a +(±2) per mil difference. This value shows reasonable agreement with interpolated 20°C equilibrium values of between +7.5 to +9.8 obtained from the literature.
|Number of pages||11|
|Journal||Applied physics communications|
|Publication status||Published - Mar 1988|