THE STRUCTURE OF LA4TI9O24 FROM SYNCHROTRON X-RAY-POWDER DIFFRACTION

The structure of La4Ti9O24 has been solved ab initio from synchrotron X-ray powder diffraction data, and the model refined using the Rietvel d method. The material crystallizes in orthorhombic spacegroqp Fddd (N o. 70) with lattice parameters a = 14.1458 (1)Angstrom, b = 35.5267 (4 )Angstrom and c = 14.5794 (1)Angstrom. Refinement proceeded to final a greement values of R(p) = 15.2% and R(wp) = 18.41%. The structure cons ists of a complex network of distorted, octahedrally-coordinated titan ium sharing corners and edges with each other and linked by two six co ordinated and one eight coordinated lanthanum atom. The distortions of the TiO6 coordination polyhedra show some similarities to those seen in other titanate materials.