Crystal structure of LaCuOS1−xSex oxychalcogenides

Solid solutions of LaCuOS1-xSex oxychalcogenides were prepared by solid-statereaction. The crystal structure of the solid solutions was refined by the Rietveldanalysis. The Rietveld analysis revealed that S or Se ions dissolve completely in thesystem of LaCuOS-LaCuOSe. The crystal structure remains almost unchanged amongthe solid solutions except for a slight variation in the lattice constants. A difference inionic radius between S and Se ions is responsible for the variation in the latticeconstants. Long interatomic distances between La and S/Se estimated from the refinedstructure supported that the crystal structure of LaCuOS1-xSex can be visualized as alayered structure composed of La-O and Cu-S/Cu-Se layers.