Short-range order in the Ca sub 1-x La sub x F sub 2+x solid solution: 1:0:3 or 1:0:4 clusters

Journal Article · Tue Aug 01 04:00:00 EDT 1989 · Journal of Solid State Chemistry; (USA)

DOI:https://doi.org/10.1016/0022-4596(89)90014-5· OSTI ID:7156698

Laval, J P; Abaouz, A; Frit, B ^[1]

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1. CNRS, Limoges (France)

The defect structure of the Ca{sub 1-x}La{sub x}F{sub 2+x} solid solution (0 {le} x {le} 0.38) has been examined at room temperature by powder neutron diffraction. Two kinds of (xxx) interstitial anions, whose respective numbers increase linearly with increasing dopant cation concentration, have been found: one labeled F{sup 0} (x {approx} 0.41) is a true interstitial; the other labeled F{sup {prime}{double prime}} (x {approx} 0.31) can be considered a relaxed normal anion. Two 1:0:n defect clusters are compatible, within the experimental errors, with these results: the 1:0:3 (1V{sub F}, OF{prime}, 3F{sup {double prime}}, 2 La{sup 3+}) and the 1:0:4 (1V{sub F}, OF{prime}, 4F{sup {double prime}}, 3La{sup 3+}) clusters. Charge balance considerations and comparisons with the homologous Ca{sub 1-x}M{sub x}{sup IV}F{sub 2+2x} solid solutions (M{sup IV} = Th, U) allow us to think that the less dense 1:0:3 cluster is present for the whole domain of both kinds of solid solutions.

• OSTI ID: 7156698
• Journal Information: Journal of Solid State Chemistry; (USA), Journal Name: Journal of Solid State Chemistry; (USA) Vol. 81:2; ISSN JSSCB; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360000* -- Materials
360100 -- Metals & Alloys
360102 -- Metals & Alloys-- Structure & Phase Studies
ALKALINE EARTH METALS
CALCIUM
COHERENT SCATTERING
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DATA
DATA ANALYSIS
DIFFRACTION
DISPERSIONS
ELEMENTS
EXPERIMENTAL DATA
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
INFORMATION
LANTHANUM COMPOUNDS
LANTHANUM FLUORIDES
MEASURING INSTRUMENTS
MEASURING METHODS
METALS
MIXTURES
NEUTRON DIFFRACTION
NUMERICAL DATA
RARE EARTH COMPOUNDS
SCATTERING
SOLID SOLUTIONS
SOLUTIONS