Un nouveau conducteur ionique (LaO)AgS

The compound (LaO)AgS is prepared by reaction of Ag₂S and La₂O₂S, in the presence of a small proportion of iodine, between 580 and 640°C. The cell is tetragonal, space group $\text{P4}\text{n}$ or $\text{P4}\text{nmm}$. The structure is not known, but is probably formed by alternating (LaO) and (AgS) sheets. The electric conductivity is determined by the complex impedance method, with blocking electrode, and by emf measurements; it is mainly ionic, with σ = 10^?3 to 10^?1 Ω^?1 cm^?1 between 25 and 250°C. The activation energy is 0.195 ± 0.005 eV.