Crystal structure and electronic structure of the La_1-xK_xCo_1-xNb_xO₃ oxides

Abstract

The La 1−x K x Co 1−x Nb x O 3 oxides were prepared by conventional solid state reaction technique. By using the GSAS programme a successful fit (Rp = 3.45%, Rwp = 2.77%, X 2 = 1.28) was obtained, for x = 0.1. Refinements confirmed that K occupying the La sites and Nb for Co sites gave an acceptable occupancy factor for K and Nb. The valence state of all the ions in the system was determined by XPS analysis, and the lattice parameters were calculated according to the results of selected-area-diffraction (SAD) patterns and X-ray diffraction (XRD) identifications. The direction of the superlattice structure along [001] was found for x = 0.1 as identified from the SAD patterns.