Pyrochlore-type oxide ceramics were studied by using electrochemical methods. The results of using H concentration cell techniques indicated that the conduction was ionic. The conducting ions under these conditions were proved to be protons by means of electrochemical H permeation experiments. These results indicated the operation of mixed, proton and electron, conduction under water-vapor concentration-cell conditions.

T.Shimura, M.Komori, H.Iwahara: Solid State Ionics, 1996, 86-88[1], 685-9