The crystal structures of some doped and undoped alkaline earth cerate perovskites

Journal Article · Wed Mar 01 04:00:00 EST 1995 · Materials Research Bulletin

DOI:https://doi.org/10.1016/0025-5408(95)00009-7· OSTI ID:27978

Knight, K S ^[1]; Bonanos, N ^[2]

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1. Rutherford Appleton Lab., Chilton (United Kingdom). ISIS Science Div.
2. Risoe National Lab., Roskilde (Denmark). Materials Dept.

The room temperature crystal structures of undoped and doped barium and strontium cerate perovskite have been refined from medium-resolution, neutron time-of-flight powder diffraction data. The compounds BaCeO{sub 3}, SrCeO{sub 3}, BaCe{sub 0.85}Pr{sub 0.15}O{sub 3} and SrCe{sub 0.95}Yb{sub 0.05}O{sub 2.975} all crystallize in the orthorhombic space group Pmcn with the GdFeO{sub 3} structure type. The crystal structure of SrCeO{sub 3} was solved from high-resolution neutron powder data by determining the magnitudes of the octahedron tilt angles from the pseudocubic lattice constants, and then refining the two structural alternatives using the Rietveld method to determine the correct structure. The structures of both doped samples are only slightly different from those of the undoped ones, reflecting the good lattice match of these ions for Ce{sup 4+}. The extrinsic anion vacancy could not be located unambiguously in SrCe{sub 0.95}Yb{sub 0.05}O{sub 2.975} and was found to be absent in BaCe{sub 0.85}Pr{sub 0.15}O{sub 3} in keeping with the expected stoichiometry. This contrasts with BaCe{sub 0.9}Y{sub 0.1}O{sub 2.95} where the vacancy was located on O2.

• OSTI ID: 27978
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Journal Issue: 3 Vol. 30; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
CERIUM OXIDES
CRYSTAL STRUCTURE
DOPED MATERIALS
EFFICIENCY
FUEL CELLS
NEUTRON DIFFRACTION
PRASEODYMIUM OXIDES
STRONTIUM OXIDES
YTTERBIUM OXIDES