Influence of crystal structure and chemical composition on the energy transfer processes in uranates

Journal Article · Fri Aug 15 00:00:00 EDT 1980 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.440304· OSTI ID:5187085

Krol, D M; Ros, J P.M.; Roos, A

The luminescence properties of several uranates are reported. The compounds that have been investigated are Y/sub 6/UO/sub 12/, Li/sub 4/UO/sub 5/, Li/sub 2/UO/sub 4/, and MgUO/sub 4/, all of which contain distorted uranate octahedra. Emission and excitation spectra and the quantum efficiency of the luminescence were measured at 4.2 K. Furthermore, the temperature dependence of the luminescence was investigated. The results show that the excitation energy migrates through the lattice and that the luminescence occurs from uranate centers near defects. These centers act as traps for the migrating excitation energy. The quantum efficiency of the luminescence varies strongly within this series of compounds. This is ascribed to a variation in the concentratio ratio of traps and killers (U/sup 5 +/ ions). When the energy migration process is described with a diffusion model, the diffusion coefficient appears to be >5 x 10/sup -8/ cm/sup 2/ s/sup -1/. Finally, some more specific results are presented for Y/sub 6/UO/sub 12/, Li/sub 4/UO/sub 5/, and Li/sub 2/UO/sub 4/.

• Research Organization: Physical Laboratory, State University, P. O. Box 80.000, 3508 TA Utrecht, The Netherlands
• OSTI ID: 5187085
• Journal Information: J. Chem. Phys.; (United States), Vol. 73:4
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
LITHIUM COMPOUNDS
EMISSION SPECTRA
FLUORESCENCE
MAGNESIUM COMPOUNDS
YTTRIUM COMPOUNDS
CRYSTAL STRUCTURE
ENERGY TRANSFER
TEMPERATURE DEPENDENCE
ULTRALOW TEMPERATURE
URANATES
ACTINIDE COMPOUNDS
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
LUMINESCENCE
SPECTRA
TRANSITION ELEMENT COMPOUNDS
URANIUM COMPOUNDS
360603* - Materials- Properties