Ionic conduction in these non-perovskite oxides was investigated at high temperatures. Fluorite-related LaxWO3+x/2 (where x was equal to 6) exhibited protonic conduction in H-containing atmospheres. The emf of a H concentration cell showed that the ionic transport number in H was between 0.7 and 0.9. An electrochemical H-pumping experiment, using LaxWO3+x/2, directly demonstrated protonic conduction in this material. The partial substitution of Zr for La decreased the electrical conductivity, but the effect of Nd substitution was small. The conductivity of aragonite-type LaBO3 was increased by doping with Sr, but the conductivities of the ceramics were not high. The emf values of a H concentration cell, with LaBO3, were stable and were close to the theoretical values; thus suggesting that electrical conduction in this material was due to protons.

Proton Conduction in Non-Perovskite-Type Oxides at Elevated Temperatures. T.Shimura, S.Fujimoto, H.Iwahara: Solid State Ionics, 2001, 143[1], 117-23