Crystal structures of some fluorite-related M/sub 7/O/sub 12/ compounds
Journal Article
·
· J. Solid State Chem.; (United States)
Powder X-ray diffraction techniques have been used to determine the crystal structures of Ti/sub 3/Sc/sub 4/O/sub 12/, Nb/sub 1/./sub 5/Sc/sub 5/./sub 5/O/sub 12/, NbSc/sub 6/O/sub 11/F, NbSc/sub 5/HfO/sub 12/, Zr/sub 3/Er/sub 4/O/sub 12/, and Hf/sub 3/Sc/sub 4/O/sub 12/ and to reexamine the structures of Zr/sub 3/Sc/sub 4/O/sub 12/ and Zr/sub 3/Yb/sub 4/O/sub 12/. All the compounds have the same fluorite-related superstructure as reported previously for Pr/sub 7/O/sub 12/, UY/sub 6/O/sub 12/, Zr/sub 3/Sc/sub 4/O/sub 12/, and Zr/sub 3/Yb/sub 4/O/sub 12/. Most of the compounds exhibit cation ordering, a situation observed previously only in UY/sub 6/O/sub 12/. One-seventh of the cations occupy a set of special sites of symmetry 3 and are octahedrally coordinated by oxygen. These cations are of the type that has the smallest available ionic radius. The remaining cations occupy a set of general sites randomly with respect to atom type and are sevenfold coordinated by oxygen. In Hf/sub 3/Sc/sub 4/O/sub 12/, only partial ordering of this nature occurs, while it is confirmed that no cation ordering occurs in Zr/sub 3/Sc/sub 4/O/sub 12/. Some aspects of the cation order-disorder situation are discussed.
- Research Organization:
- CSIRO, Melbourne
- OSTI ID:
- 7317788
- Journal Information:
- J. Solid State Chem.; (United States), Journal Name: J. Solid State Chem.; (United States) Vol. 19:2; ISSN JSSCB
- Country of Publication:
- United States
- Language:
- English
Similar Records
{delta}-Phase to defect fluorite (order-disorder) transition in the R{sub 2}O{sub 3}-MO{sub 2} (R = Sc, Tm, Lu; M = Zr, Hf) systems
Ordering in HfO/sub 2/-Ln/sub 2/O/sub 3/ systems where Ln is Dy, Er, or Yb
WTh{sub 8}Zr{sub 18}F{sub 4}O{sub 53}: A new superstructure of fluorite type, associating anion-excess and anion-deficient blocks
Journal Article
·
Fri Apr 15 00:00:00 EDT 2011
· Materials Research Bulletin
·
OSTI ID:22210039
Ordering in HfO/sub 2/-Ln/sub 2/O/sub 3/ systems where Ln is Dy, Er, or Yb
Journal Article
·
Mon Dec 31 23:00:00 EST 1979
· High Temp. Sci.; (United States)
·
OSTI ID:6233050
WTh{sub 8}Zr{sub 18}F{sub 4}O{sub 53}: A new superstructure of fluorite type, associating anion-excess and anion-deficient blocks
Journal Article
·
Tue Feb 14 23:00:00 EST 1995
· Journal of Solid State Chemistry
·
OSTI ID:508686
Related Subjects
36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
CATIONS
CHALCOGENIDES
CHARGED PARTICLES
COHERENT SCATTERING
CRYSTAL STRUCTURE
DIFFRACTION
HAFNIUM COMPOUNDS
HAFNIUM OXIDES
IONS
NIOBIUM COMPOUNDS
NIOBIUM OXIDES
ORDER PARAMETERS
OXIDES
OXYGEN COMPOUNDS
RARE EARTH COMPOUNDS
SCATTERING
SUPERLATTICES
SYMMETRY
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
CATIONS
CHALCOGENIDES
CHARGED PARTICLES
COHERENT SCATTERING
CRYSTAL STRUCTURE
DIFFRACTION
HAFNIUM COMPOUNDS
HAFNIUM OXIDES
IONS
NIOBIUM COMPOUNDS
NIOBIUM OXIDES
ORDER PARAMETERS
OXIDES
OXYGEN COMPOUNDS
RARE EARTH COMPOUNDS
SCATTERING
SUPERLATTICES
SYMMETRY
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION