Rietveld refinement of KLaTiO(4) from X-ray powder data

Potassium lanthanum titanate(IV), KLaTiO(4), has been synthesized by conventional solid-state reaction. It crystallizes isotypically with the NaLnTiO(4) (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 TiO(6) octa-hedra extending parallel to (001). The layers are alternately separated by K(+) and La(3+) cations along [001]. The coordination number of both K(+) and La(3+) cations is nine, resulting in distorted KO(9) and LaO(9) polyhedra.