Bi{sub 2}La{sub 4}O{sub 9}: A monoclinic phase in the system Bi{sub 2}O{sub 3}-La{sub 2}O{sub 3}

Journal Article · Mon Jul 01 04:00:00 EDT 1996 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1006/jssc.1996.0240· OSTI ID:494453

Chen, X L; Eysel, W ^[1]; Li, J Q ^[2]

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1. Universitaet Heidelberg (Germany)
2. Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany)

The binary system Bi{sub 2}O{sub 3}-La{sub 2}O{sub 3} with La{sub 2}O{sub 3} {ge} 50 mole% has been investigated at 950-1000{degrees}C. The results revealed three compounds: Bi{sub 8}La{sub 10}O{sub 27}, Bi{sub 2.4}La{sub 3.6}O{sub 9}, and Bi{sub 2}La{sub 4}O{sub 9}. Bi{sub 2.4}La{sub 3.6}O{sub 9} has a rhombohedral subcell with hexagonal lattice parameters a = 3.9601(5) {Angstrom}, c = 9.9691(2) {Angstrom}, and space group R3m. It is probably the same phase which was reported previously as Bi{sub 2}La{sub 4}O{sub 9} (Refs. 5 and 6). Bi{sub 2}La{sub 4}O{sub 9} has a monoclinic structure with the subcell lattice parameters a = 6.8290(3) {Angstrom}, b = 3.9887(1) {Angstrom}, c = 4.0524(1) {Angstrom} and {beta} = 125.094(3){degrees} and subcell space group C2/m. Its average structure has been determined by X-ray powder diffraction and refined by the Rietveld method. The average structure can be described as an oxygen deficient fluorite structure of the {delta}-Bi{sub 2}O{sub 3} type with La and Bi randomly distributed on the cation site. In addition, a superstructure has been observed by TEM.

• OSTI ID: 494453
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 2 Vol. 124; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BISMUTH OXIDES
HEXAGONAL LATTICES
LANTHANUM OXIDES
MONOCLINIC LATTICES
PHASE STUDIES
TRANSMISSION ELECTRON MICROSCOPY
TRIGONAL LATTICES
X-RAY DIFFRACTION