Ionic conduction in hydrated zeolite Li-, Na- and K-A at high pressures

Abstract

Ionic conductivities of hydrated zeolite Li-, Na- and K-A at room temperature and at pressures up to 4.8 GPa have been measured. Anomalous increases in conductivity with pressure up to 1.7–1.9 GPa were observed for all zeolites. In this pressure range, activation volumes of conduction are −1.4, −3.9 and −6.8 cm 3/mol for Li-, Na- and K-A zeolites, respectively. The conductivity goes through a maximum, where pressure-induced amorphization occurs. Following the maximum, there is a rapid decrease in conductivity due to the collapse of long-range ordering. On decompression, conductivity increases to values that are higher than the conductivity values at equal pressures on compression.