The non-stoichiometric mixed perovskite, Ba3(Ca1.18Nb1.82)3O9, was shown to become a good high-temperature protonic conductor upon exposure to H2O or D2O atmospheres. The conductivity was studied at temperatures ranging from 300 to 550K, where the

proton concentration was frozen-in. The activation energies for proton migration in this compound was 0.54eV. The conductivities were of the same order as those of M3+-doped SrCeO3 and BaCeO3, but the present material did not exhibit electronic conduction after treatment in highly reducing atmospheres.

K.C.Liang, D.Yang, A.S.Nowick: Solid State Ionics, 1994, 69[2], 117-20

Table 20

Proton Conductivity of Ba3Nb2-xCa1-xO9