Materials Research Bulletin, Vol.34, No.14-15, 2193-2199, 1999
On a lead nickel manganese tellurium oxide PbMn2Ni6Te3O18 containing Mn2+ in trigonal prismatic oxygen coordination
A new lead manganese nickel tellurium oxide PbMn2Ni6Te3O18 is light green in color and crystallizes in hexagonal symmetry, space group C-6h(2), P6(3)/m (no. 176), with cell parameters a = 9.294(1), c = 8.823(1) Angstrom, and Z = 2. The structure was determined from a single crystal X-ray study and refined to the conventional values R = 0.026 and wR(F-2) = 0.046. Ni2+ and Te6+ show octahedral and Mn2+ shows trigonal prismatic coordination by O2-. The crystal structure is featured by a (2)(infinity)[Ni6Te3O18](6-) network together with two kinds of channels along [001] with trigonal and hexagonal shape. Isolated face shared [Mn2O9](14-) trigonal prismatic polyhedra doubles are located in the trigonal channels, while one-dimensional infinite chains of [PbO6+6](22-) oxygen cube dodecahedra are incorporated in the hexagonal channels,
Keywords:CRYSTAL-STRUCTURE