The effect of hydrostatic pressure on the structure sensitive ionic conductivity in KCl

摘要: Abstract The carriers of the ionic current in alkali halides structure sensitive range are cation vacancies predominantly due to presence divalent cationic impurities dissolved substitutionally crystal. Conductivity ‘pure’ (Harshaw) and ‘doped’ (10 −4 mole fraction Sr ++ ) KCl has been measured this (50–300°C) at pressures up 4 kbars. Measurements were made using argon a conventional pressure system applying standard electrometer techniques. vessel had electrical leads high resistance low capacitance. Results obtained Harshaw show three distinct regions which can be identified as extrinsic unassociated, associated, precipitation regions. volume motion free is found 8.6 (cm 3 /mole) association (divalent impurity-cation vacancy) pair 3.6 /mole). solution from measurements region increases 6 10 with decreasing temperature. dependence conductivity agreement qualitative features Stasiw-Teltow theory, should applicable for concentration (about ppm) (in KCl). on none seen same temperature range. behavior material related impurity. results compared similar by Pierce Biermann higher temperatures. discussed means understanding processes operating various temperatures impurity concentrations. Finally, theoretical calculations activation volumes, especially motion, proposed possible indication suitability particular form repulsive interionic potential.