Ionic conduction in single-crystal zeolite (figure 10) was reported for the first time. Sub-millimeter sized ferrierite was grown by an organothermal method, and the conduction of sodium cation was measured along [001] and [010] separately by ac impedance analysis. The main conduction along [001] was through ten-member ring channels, while that along [010] was through eight-member ring channels. Measurements at 673 to 873K revealed that the conductivity along [010] was greater than that along [001]. The activation energy along [010] (1.2eV) was greater than that (0.84eV) along [001].

Ionic Conductivity of Single-Crystal Ferrierite. N.Yamamoto, T.Okubo: Microporous and Mesoporous Materials, 2000, 40[1-3], 283–8