Impedance Measurements on Lithium‐Electrolyzed Borosilicate Glass

Commercial Pyrex glass was electrolyzed with and , thereby replacing sodium by lithium. A‐C impedance measurements on these glasses were made at temperatures ranging from 380° to 520°C and at frequencies from 50 kHz up to 6 MHz. Both electrolysis and impedance measurements took place in molten zinc chloride. Resistivities of mixtures containing approximately equal amounts of 6 Li and 7 Li showed positive deviations from linearity at 400°–450°C. Activation energies showed maxima at the same concentrations. It was concluded that the lithium‐electrolyzed borosilicate glass showed a mixed isotope effect.