Synthesis and crystal structure of Bi6(Bi0.5Cu0.5)V2O15+y

Abstract The structure of the oxide with composition Bi 6 (Bi 0.5 Cu 0.5 )V 2 O 15+ y has been solved based on single crystal X-ray diffraction and is found to be monoclinic (S. G. I2 ), a =11.276(1) A, b =5.4513(2) A, c =11.055(3) A, β =96.70°(1). The crystal was twinned by 180° rotoinversion about [ 1 ¯ 0 1] in the direct lattice as found in the the phosphates, Bi 6 TiP 2 O 16 and Bi 6+ x M 1− x P 2 O 15+ y (M=Mn, Fe and Ni), wherein chains of edge sharing (OBi 4 ) tetrahedral units are connected by layers of VO 4 tetrahedra and (Bi/Cu)O 6− x ( x =oxygen vacancies) octahedra.