A niobium phosphate with a tunnel structure: Ca sub 0. 5+x Cs sub 2 Nb sub 6 P sub 3 O sub 24
Journal Article
·
· Journal of Solid State Chemistry; (USA)
- Universite de Caen (France)
A new niobium phosphate, Ca{sub 0.5+x}Cs{sub 2}Nb{sub 6}P{sub 3}O{sub 24} has been isolated. It crystallizes in the R32 space group, with the following parameters of the hexagonal cell: a{sub H} = 13.379 {angstrom}, c{sub H} = 10.371 {angstrom}. The determination of the structure by a single crystal X-ray diffraction study shows that its host lattice (Nb{sub 6}P{sub 3}O{sub 24}){sub {infinity}} can be described as the assemblage of mixed chains (Nb{sub 2}PO{sub 13}){sub {infinity}} running along c{sub H} in which one PO{sub 4} tetrahedron alternates with two NbO{sub 6} octahedra. This framework delimits huge tunnels where the cesium cations are located and cages formed by (Nb{sub 6}P{sub 3}O{sub 36}) units occupied by calcium. The most striking feature of this framework deals with its similarity with the hexagonal tungsten bronze of Magneli (HTB). The latter is discussed here by considering the stacking along c of (Nb{sub 2}PO{sub 8}){sub {infinity}} layers whose geometry is closely related to that of the HTBs. The possibility of nonstoichiometry leading to a mixed valency of niobium is considered.
- OSTI ID:
- 5558830
- Journal Information:
- Journal of Solid State Chemistry; (USA), Journal Name: Journal of Solid State Chemistry; (USA) Vol. 90:2; ISSN 0022-4596; ISSN JSSCB
- Country of Publication:
- United States
- Language:
- English
Similar Records
A niobium phosphate bronze closely related to the tungsten phosphate bronzes family: Na sub 4 Nb sub 8 P sub 6 O sub 35
A novel niobium phosphate bronze with a tunnel structure, K sub 3 Nb sub 6 P sub 4 O sub 26 , member n = infinity of the series (K sub 3 Nb sub 6 P sub 4 O sub 26 ) n ter dot KNb sub 2 PO sub 8
A phosphoniobate with an intersecting tunnel structure related to pyrochlore: Rb[sub 3]Nb[sub 5]P[sub 2]O[sub 19]
Journal Article
·
Wed Oct 31 23:00:00 EST 1990
· Journal of Solid State Chemistry; (USA)
·
OSTI ID:5943568
A novel niobium phosphate bronze with a tunnel structure, K sub 3 Nb sub 6 P sub 4 O sub 26 , member n = infinity of the series (K sub 3 Nb sub 6 P sub 4 O sub 26 ) n ter dot KNb sub 2 PO sub 8
Journal Article
·
Wed Jan 31 23:00:00 EST 1990
· Journal of Solid State Chemistry; (USA)
·
OSTI ID:7198971
A phosphoniobate with an intersecting tunnel structure related to pyrochlore: Rb[sub 3]Nb[sub 5]P[sub 2]O[sub 19]
Journal Article
·
Fri Jul 01 00:00:00 EDT 1994
· Journal of Solid State Chemistry; (United States)
·
OSTI ID:6836978
Related Subjects
36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
CALCIUM COMPOUNDS
CALCIUM PHOSPHATES
CESIUM COMPOUNDS
CESIUM PHOSPHATES
COHERENT SCATTERING
CRYSTAL STRUCTURE
DATA
DATA ANALYSIS
DIFFRACTION
EXPERIMENTAL DATA
INFORMATION
LATTICE PARAMETERS
NIOBIUM COMPOUNDS
NIOBIUM PHOSPHATES
NUMERICAL DATA
OXYGEN COMPOUNDS
PHOSPHATES
PHOSPHORUS COMPOUNDS
REFRACTORY METAL COMPOUNDS
SCATTERING
SPACE GROUPS
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION
360602* -- Other Materials-- Structure & Phase Studies
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
CALCIUM COMPOUNDS
CALCIUM PHOSPHATES
CESIUM COMPOUNDS
CESIUM PHOSPHATES
COHERENT SCATTERING
CRYSTAL STRUCTURE
DATA
DATA ANALYSIS
DIFFRACTION
EXPERIMENTAL DATA
INFORMATION
LATTICE PARAMETERS
NIOBIUM COMPOUNDS
NIOBIUM PHOSPHATES
NUMERICAL DATA
OXYGEN COMPOUNDS
PHOSPHATES
PHOSPHORUS COMPOUNDS
REFRACTORY METAL COMPOUNDS
SCATTERING
SPACE GROUPS
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION