Crystal chemistry, magnetic, and electrical properties of hexagonal plutonium oxide chalcogenides: Pu/sub 2/O/sub 2/X, X = O, S, Se

Journal Article · Fri Apr 01 04:00:00 EST 1983 · J. Solid State Chem.; (United States)

DOI:https://doi.org/10.1016/0022-4596(83)90009-9· OSTI ID:5687719

Costantini, J M ^[1]; Novion, C H; Blaise, A; Cousson, A; Abazli, H; Pages, M

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1. DECPu-SEFCAE, CEN Fontenay-aux-Roses, France

A study was made of the influence of the chalcogen X on the magnetic and electrical properties of Pu/sub 2/O/sub 2/X (X=O,S,Se) compounds and on bonding in these hexagonal compounds, isostructural with the corresponding rare-earth compounds. The comparison of the cell volumes of Nd/sub 2/O/sub 2/X and Pu/sub 2/O/sub 2/X compounds showed that the Pu/sup 3 +/ crystal radius decreased from ..beta..-Pu/sub 2/O/sub 3/ to Pu/sub 2/O/sub 2/Se as ''5f delocalization'' and 5f-p overlap increased. These plutonium compounds were all found to be antiferromagnetic. This was caused by superexchange coupling interactions via p orbitals of the oxygen and chalcogen ions. The Neel temperature increased from ..beta..-Pu/sub 2/O/sub 3/ (26 K) to Pu/sub 2/O/sub 2/S (28 K) then to Pu/sub 2/O/sub 2/Se (34 K) showing that 5f-p covalency was enhanced as the chalcogen electronegativity decreased and the p radial extent increased. The hexagonal ..beta..-Pu/sub 2/O/sub 3/ was found to be an insulator while both other compounds were semiconductors with gaps around 0.5 eV. These gaps were interpreted as the energy separation between the 6d-7s conduction band and the np band of the chalcogen X with some overlap of the occupied 5f states and the np band. A simple electron band scheme of these compounds is proposed on such assumptions.

• OSTI ID: 5687719
• Journal Information: J. Solid State Chem.; (United States), Journal Name: J. Solid State Chem.; (United States) Vol. 47:2; ISSN JSSCB
• Country of Publication: United States
• Language: English

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ACTINIDE COMPOUNDS
BAND THEORY
CHALCOGENIDES
CHEMICAL BONDS
CHEMICAL PROPERTIES
COMPARATIVE EVALUATIONS
CRYSTAL STRUCTURE
MAGNETIC PROPERTIES
NEODYMIUM COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PLUTONIUM COMPOUNDS
PLUTONIUM OXIDES
PLUTONIUM SELENIDES
PLUTONIUM SULFIDES
RARE EARTH COMPOUNDS
SELENIDES
SELENIUM COMPOUNDS
SULFIDES
SULFUR COMPOUNDS
TRANSURANIUM COMPOUNDS