Preparation and crystal structure of K/sub 2/Nb/sub 2/As/sub 2/O/sub 11/
K/sup 2/Nb/sub 2/As/sub 2/O/sub 11/ crystallizes in the monoclinic system, space group P21/a, with a = 10.342(6), b = 10.446(5), c = 9.971(4) A, ..beta.. = 96.72(4)/sup 0/, M = 589.86, V = 1069.8(5) A/sup 3/, Z = 4, rho = 3.67 g cm/sup -1/. The crystal structure was refined (105 variables) from 1782 independent reflections collected on a Philips PW 1100 automatic diffractometer with AgK anti ..cap alpha.. radiation. The final R index and weighted R/sub w/ index are 0.058 and 0.056, respectively. The structure consists of NbO/sub 6/ octahedra and AsO/sub 4/ tetrahedra sharing vertices, forming infinite chains (NbO/sub 6/-AsO/sub 4/)infinity parallel to the a axis. Two chains are linked together by Nb-O-Nb and Nb-O-As bonds. These double chains are connected by vertices, forming a three-dimensional network. The potassium atoms are located in tunnels parallel to the a axis.
- Research Organization:
- Campus Universitaire, Tunise (Tunisie)
- OSTI ID:
- 6749483
- Journal Information:
- J. Solid State Chem.; (United States), Vol. 74:2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ARSENIC OXIDES
CRYSTAL STRUCTURE
NIOBIUM OXIDES
POTASSIUM OXIDES
CHEMICAL PREPARATION
EXPERIMENTAL DATA
MONOCLINIC LATTICES
SPACE GROUPS
X-RAY DIFFRACTION
ALKALI METAL COMPOUNDS
ARSENIC COMPOUNDS
CHALCOGENIDES
COHERENT SCATTERING
CRYSTAL LATTICES
DATA
DIFFRACTION
INFORMATION
NIOBIUM COMPOUNDS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
POTASSIUM COMPOUNDS
REFRACTORY METAL COMPOUNDS
SCATTERING
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
360202* - Ceramics
Cermets
& Refractories- Structure & Phase Studies