The impedance spectra of Pb5Ge3O11 single crystals were measured in the frequency range of 5Hz to 13MHz, at 600 to 800K in dry air and in a dry or wet N gas. It was found that the temperature and the gas composition significantly affected the electrical properties of the compound. The data obtained were used to explain the origin of crystal lattice defects and their influence upon charge transfer. It was concluded that the conduction was mixed in character (p-type electronic and ionic due to O ions). Proton conduction was shown experimentally to be feasible.

Influence of the Defect Structure on the Electrical Conductivity of Pb5Ge3O11 Single Crystals at High Temperatures. V.M.Duda, A.I.Baranov, A.S.Ermakov, R.C.T.Slade: Physics of the Solid State, 2006, 48[1], 63-7