Investigations were made of high temperature proton conduction in the tetragonal tungsten bronze niobates, A0.6Ti0.2Nb0.8O3 and A0.6Mg0.067Nb0.933O3 (A = Sr, Ba). For all of the samples, the conductivities in dry N2 were higher than those in dry O2; indicating that these materials exhibited n-type electronic conduction. In wet atmospheres, the conductivities of the Ba-containing systems and Sr0.6Ti0.2Nb0.8O3 were higher than those in dry atmospheres; indicating the occurrence of proton conduction. The conductivities were low (σ600C ≈ 2 x 10−6 and 6 x 10−6S/cm in wet O2 and N2, respectively). In the case of Sr0.6Mg0.067Nb0.933O3, the conductivities were similar for both wet and dry atmospheres; apart from a small increase in conductivity below 650C in wet O2; suggesting a lower proton conductivity for this system. The low proton conductivity in these samples was attributed to a low O vacancy concentration. Attempts to vary the Ti/Nb or Mg/Nb ratio, so as to increase the oxide-ion vacancy concentration and improve the proton conduction, were unsuccessful.Investigation of Proton Conduction in the Tetragonal Tungsten Bronze Niobates - A0.6(M,Nb)O3 (A = Sr, Ba; M = Mg, Ti). E.Kendrick, M.S.Islam, P.R.Slater: Solid State Ionics, 2005, 176[39-40], 2975-8