The charge transport properties of so-called BaCuO2, with a 88:90 (Ba:Cu) cation ratio were characterized by making thermopower, conductivity and ionic transport number measurements over a wide range of temperatures and O partial pressures. It was found that the carriers were always small polarons, due to self-trapping of the holes which were generated by O non-stoichiometry. It was shown that some anomalies in the carrier mobility, as a function of temperature, were not related to incomplete ionization of O atoms on interstitial sites.

G.Chiodelli, U.Anselmi-Tamburini, M.Arimondi, G.Spinolo, G.Flor: Zeitschrift für Naturforschung, 1995, 50a[11], 1059-66