Solvolytic disproportionation of mixed-valence compounds. I. Pr/sub 7/O/sub 12/

Journal Article · Fri Jul 01 04:00:00 EDT 1988 · J. Solid State Chem.; (United States)

DOI:https://doi.org/10.1016/0022-4596(88)90302-7· OSTI ID:7044799

Kang, Z C; Eyring, L

Pr/sub 7/O/sub 12/ is an intermediate praseodymium oxide of mixed oxidation state. It is single phase with metal atoms occupying different types of crystallographic sites. In contrast with dilute acid, among other solvents, the single-phase compound loses Pr/sup 3 +/ ions to the solution and the residue is oxidized to PrO/sub 2/. The morphology of the reaction, studied by electron microscopy, indicates that the dissolution follows extended crystal defects, probably dislocations, and involves the removal of all the oxide in the reaction path. This requires the transport of oxygen and electrons in the reaction zone where praseodymium is reduced with the concomitant oxidation of material adjacent to it. This reaction occurs without the destruction of the original framework because Pr/sub 7/O/sub 12/ and the other intermediate oxides are fluorite-related and transform to fluorite-type PrO/sub 2/ without reconstruction.

• Research Organization: Arizona State Univ., Tempe (USA)
• OSTI ID: 7044799
• Journal Information: J. Solid State Chem.; (United States), Journal Name: J. Solid State Chem.; (United States) Journal Issue: 1 Vol. 75:1; ISSN JSSCB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CHALCOGENIDES
CHEMICAL REACTIONS
COHERENT SCATTERING
CRYSTAL STRUCTURE
DATA
DIFFRACTION
ELECTRON MICROSCOPY
EXPERIMENTAL DATA
INFORMATION
MICROSCOPY
NUMERICAL DATA
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PRASEODYMIUM COMPOUNDS
PRASEODYMIUM OXIDES
RARE EARTH COMPOUNDS
REDUCTION
SCATTERING
SURFACE PROPERTIES
X-RAY DIFFRACTION