Luminescence spectroscopic investigation of europium (III)-doped fluorite oxides: defect structures in CERIA and THORIA and polymorphism of zirconia

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:5356013

Kenny-McDermott, E M

Laser-excited high-resolution luminescence spectroscopy of europium (III) was used as a structure probe for investigating defect structures in CeO/sub 2/ and ThO/sub 2/, and for following the phase transitions of ZrO/sub 2/. By varying the Eu/sup +3/ concentration, adding charge-compensating agents, and changing calcination conditions in a systematic manner, perturbations in Eu/sup +3/ spectra were associated with different defect sites or crystalline phases. The /sup 5/D/sub 0/ ..-->.. /sup 7/F/sub 1/ transition, dominated the Eu/sup +3/ luminescence spectra in CeO/sub 2/ and ThO/sub 2/ indicating a distantly compensated site with cubic symmetry. Eu/sup +3/ spectra lines associated with charge compensating defects, were 50 to 100 times less intense. Ten different defect sites were observed in CeO/sub 2/ - five with a highly shifted /sup 5/D/sub 0/ ..-->.. /sup 7/F/sub 0/ and no associated /sup 5/D/sub 0/ ..-->.. /sup 7/F/sub 1/ or /sup 5/D/sub 0/ ..-->.. /sup 7/F/sub 2/ lines. These sites were assigned to oxygen vacancy dimer and single oxygen vacancy defects. The spectra of ThO/sub 2/:Eu/sup +3/ exhibited a triply split /sup 5/D/sub 0/ ..-->.. /sup 7/F/sub 1/ thought to be caused by cubic microsites within ThO/sub 2/ unit cells exhibiting different lattice parameters. The different lattice cation symmetries in m-, t-, and c-ZrO/sub 2/ produced a characteristic Eu/sup +3/ spectra which could be used to identify that crystalline phase in a sample.

• Research Organization: Seton Hall Univ., South Orange, NJ (USA)
• OSTI ID: 5356013
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ACTINIDE COMPOUNDS
CERIUM COMPOUNDS
CERIUM OXIDES
CHALCOGENIDES
CHARGED PARTICLES
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DOPED MATERIALS
EUROPIUM IONS
IONS
LUMINESCENCE
MATERIALS
OXIDES
OXYGEN COMPOUNDS
RARE EARTH COMPOUNDS
SPECTRA
THORIUM COMPOUNDS
THORIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES