Rietveld refinement of KLaTiO4 from X-ray powder data

Abstract

Potassium lanthanum titanate(IV), KLaTiO4, has been synthesized by conventional solid-state reaction. It crystallizes isotypically with the NaLnTiO4 (Ln = La, Pr, Nd, Sm, Eu, Gd, Y and Lu) family. Five of the six atoms in the asymmetric unit (one K, one La, one Ti and two O atoms) are situated on sites with 4mm symmetry, whereas one O atom has 2mm. site symmetry. The crystal structure can be described as being composed of single layers of distorted corner-sharing TiO6 octahedra extending parallel to (001). The layers are alternately separated by K+ and La3+ cations along [001]. The coordination number of both K+ and La3+ cations is nine, resulting in distorted KO9 and LaO9 polyhedra.