Materials Research Bulletin, Vol.33, No.10, 1537-1548, 1998
Crystal structure of BaLa4Ti4O15, member n = 5 of the homologous series (Ba, La)(n)Tin-1O3n of cation-deficient perovskite-related compounds
BaLa4Ti4O15 crystallizes in the trigonal system (space group ) with the unit-cell parameters a = 5.5720(10) and c = 22.500(2) Angstrom; Z = 2. The structure has been solved from single crystal X-ray diffraction data to a final R-1 = 0.0336. Ba and La atoms are 12-fold coordinated and Ti atoms are 6-fold coordinated. The structure can be described as consisting of identical perovskite-like blocks, four corner-sharing TiO6 octahedra thick, separated by layers of vacant octahedra. The distortion of the cation and anion sublattices has been analyzed and a Ba/La order has been observed.
Keywords:BOND-VALENCE PARAMETERS;OXIDES