The non-stoichiometric mixed perovskites, Sr2(Sc1+xNb1-x)O6 (where x was equal to 0.05 or 0.1), were shown to become good high-temperature protonic conductors 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 these compounds was 0.62. The conductivities were of the same order as those of M3+-doped SrCeO3 and BaCeO3.

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