Experimental investigation of point defects and motion of charge in Al/sub 2/O/sub 3/, MgO, and SrO

Thesis/Dissertation · Tue Jan 01 00:00:00 EST 1985

OSTI ID:5281847

Jeffries, B T

This study investigates the electronic structure, motion of charge, and trapping mechanisms in Al/sub 2/O/sub 3/, MgO, and SrO. Thermochemically colored, electron irradiated, neutron irradiated, and gamma irradiated single crystals are studied from 6 to 300/sup 0/K. A wide range of experimental techniques are used. For Al/sub 2/O/sub 3/, the excited state in F centers autoionizes at 6 K showing this state is in or very close to the conduction band. The Stoke's shift obtained from a photoluminescence band shape analysis does not predict the experimental emission peak energy of 3.0 eV but predicts 4.8 eV. This implies the emission occurs from a different state than the one excited into. In MgO, the sample dependent 2.3 eV phosphorescence near room temperature is directly related to the concentration of H/sup -/ ions trapped in oxygen vacancies and is not related to the F center concentration. The H/sup -/ ion is most likely responsible for the low temperature phosphorescence also. The F center interacts with the low-temperature electron trap at 10/sup 0/K showing the excited state is very near to the conduction band. A /sup 0/90/sup 0/K thermoluminescence peak in SrO produces F/sup +/ center emission which implies a bare oxygen vacancy may exist.

• Research Organization: Oklahoma State Univ., Stillwater (USA)
• OSTI ID: 5281847
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
PHYSICAL RADIATION EFFECTS
MAGNESIUM OXIDES
STRONTIUM OXIDES
ELECTRON BEAMS
ELECTRONIC STRUCTURE
F CENTERS
GAMMA RADIATION
LOW TEMPERATURE
MEDIUM TEMPERATURE
MONOCRYSTALS
NEUTRON BEAMS
PHOSPHORESCENCE
PHOTOLUMINESCENCE
POINT DEFECTS
THERMOLUMINESCENCE
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM COMPOUNDS
BEAMS
CHALCOGENIDES
COLOR CENTERS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
CRYSTALS
ELECTROMAGNETIC RADIATION
IONIZING RADIATIONS
LEPTON BEAMS
LUMINESCENCE
MAGNESIUM COMPOUNDS
NUCLEON BEAMS
OXIDES
OXYGEN COMPOUNDS
PARTICLE BEAMS
RADIATION EFFECTS
RADIATIONS
STRONTIUM COMPOUNDS
VACANCIES
360206* - Ceramics
Cermets
& Refractories- Radiation Effects