Neutron diffraction study of LaScO3-based proton conductor

The crystal structures of H2O treated 20 mol% Sr-doped LaScO3 perovskite-type oxide, (La0.8Sr0.2)ScO3H0.18 (LSS) have been investigated at 3, 150, and 298 K using a powder neutron diffraction (ND) method. All the diffraction peaks of LSS could be indexed as an orthorhombic GdFeO3-type perovskite structure (space group: Pnma, No.62) between 3 and 298 K. The Rietveld refinement and subsequent maximum-entropy-method (MEM) analysis results of ND data at 3 K revealed that protons are associated with the O1 oxygen (4c) site in the La and Sr containing mirror plane and exist in the space consists of two tilting ScO6 octahedra. The O1H bond distance was found to be 1.12(2) إ at 3 K.