A Ionic Conductivity Study of Impurity-Vacancy Association in Silver-Chloride
Abstract
Ionic conductivity data were taken for silver chloride specimens doped with various kinds (Ca, Mn, Ni, and Zn) and amounts (5 ppm - 300 ppm) of divalent cation impurities, over a temperature range of 20 degrees to 350 degrees Celsius. The data were computer fit by a nonlinear least squares algorithm to the Lidiard-Debye-Huckel model, resulting in values of the enthalpy and entropy of association between each type of divalent impurity and a silver vacancy. The association enthalpies for Ca, Mn, Ni, and Zn were found to be 0.34, 0.25, 0.24, and 0.61 electron volts, respectively. All values are considered reliable to + or - 0.01 electron volt with the exception of the value for the zinc-doped crystals, which is considered good only to + or - 0.06 electron volts; the smaller confidence due primarily to the low solubility of zinc in silver chloride. These values of association enthalpy compare favorably with results determined by EPR and diffusion experiments.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1974
- Bibcode:
- 1974PhDT........28G
- Keywords:
-
- Physics: Condensed Matter;
- Ion Currents;
- Silver Chlorides;
- Vacancies (Crystal Defects);
- Impurities;
- Least Squares Method;
- Nonlinear Equations;
- Temperature Effects;
- Solid-State Physics