Influence of crystal structure on the luminescence of tantalates and niobates
The luminescence of MgTa/sub 2/O/sub 6/ (trirutile structure) and ZnTa/sub 2/O/sub 6/ (tri-..cap alpha..-PbO/sub 2/ structure) are reported and discussed in connection with the luminescence of related compounds, especially the niobates with columbite structure. The maximum of the excitation band of the luminescence of the two tantalates is at 280 nm, a value lower in energy than that for the niobates. The emission band has its maximum at 500 nm (MgTa/sub 2/O/sub 6/) and 450 nm (ZnTa/sub 2/O/sub 6/). The quantum efficiency is low, reaching 15% (MgTa/sub 2/O/sub 6/) and 30% (ZnTa/sub 2/O/sub 6/) at 4.2 K. It is argued that the phenomena observed for these compounds indicate that the excitons, formed upon photoexcitation, are mobile, whereas in the columbite niobates they are localized due to self-trapping.
- Research Organization:
- Utrecht Univ. (Netherlands)
- OSTI ID:
- 7078480
- Journal Information:
- J. Solid State Chem.; (United States), Journal Name: J. Solid State Chem.; (United States) Vol. 72:1; ISSN JSSCB
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKALINE EARTH METAL COMPOUNDS
CRYSTAL STRUCTURE
DATA
EMISSION SPECTROSCOPY
EXPERIMENTAL DATA
INFORMATION
LUMINESCENCE
MAGNESIUM COMPOUNDS
NIOBATES
NIOBIUM COMPOUNDS
NUMERICAL DATA
OPTICAL PROPERTIES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
REFRACTORY METAL COMPOUNDS
SPECTROSCOPY
TANTALATES
TANTALUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
ZIRCONIUM COMPOUNDS