Synthesis and structure of Ln sub 2 Ta sub 3 Se sub 2 O sub 8 (Ln = La, Ce, Pr, Nd)

Journal Article · Mon Apr 01 04:00:00 EST 1991 · Journal of Solid State Chemistry; (USA)

DOI:https://doi.org/10.1016/0022-4596(91)90086-W· OSTI ID:5744050

Brennan, T; Aleandri, L; Ibers, J ^[1]

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1. Northwestern Univ., Evanston, IL (USA)

A series of compounds Ln{sub 2}Ta{sub 3}Se{sub 2}O{sub 8}(Ln = La, Ce, Pr, Nd) has been prepared and characterized. Pr{sub 2}Ta{sub 3}Se{sub 2}O{sub 8} is orthorhombic, space group D{sub 2h}{sup 12}{minus}Pnnm, with unit cell constants a = 9.882(3), b = 11.774(3), c = 7.601(2) {angstrom}, T = 111 K, Z = 4. The structure has been solved and refined from single crystal x-ray diffraction data. The structure, including the oxygen content and positions, has been confirmed from neutron diffraction powder data. The asymmetric unit contains two independent Pr atoms, two independent Ta atoms, two independent Se atoms, five independent O atoms. The Pr atoms are in tricapped-trigonal prismatic sites enclosed by seven O and two Se atoms. One Ta atom is in a distorted octahedral site surrounded by six O atoms, and the other Ta atom is also in a distorted octahedral environment but has two trans O and four Se atoms in its coordination sphere.

• OSTI ID: 5744050
• Journal Information: Journal of Solid State Chemistry; (USA), Journal Name: Journal of Solid State Chemistry; (USA) Vol. 91:2; ISSN 0022-4596; ISSN JSSCB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
CERIUM COMPOUNDS
CERIUM OXIDES
CHALCOGENIDES
CHEMICAL PREPARATION
COHERENT SCATTERING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DATA
DIFFRACTION
EXPERIMENTAL DATA
INFORMATION
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
LATTICE PARAMETERS
NEODYMIUM COMPOUNDS
NEODYMIUM OXIDES
NUMERICAL DATA
ORTHORHOMBIC LATTICES
OXIDES
OXYGEN COMPOUNDS
PRASEODYMIUM COMPOUNDS
PRASEODYMIUM OXIDES
RARE EARTH COMPOUNDS
REFRACTORY METAL COMPOUNDS
SCATTERING
SELENIUM COMPOUNDS
SELENIUM OXIDES
SPACE GROUPS
SYNTHESIS
TANTALUM COMPOUNDS
TANTALUM OXIDES
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION