Point defects in topaz crystals
Journal Article
·
· Appl. Phys. Commun.; (United States)
OSTI ID:6224431
Topaz is a wide band gap insulating silicate crystal with four Al/sub 2/F/sub 2/SiO/sub 4/ formula units per orthorhombic unit cell, and isolated SiO/sub 4/ tetrahedra. They have used ESR, polarized optical absorption, and isochronal annealing to study the point defects introduced into the lattice by radiation damage. Following irradiation, the ESR spectrum is dominated by a single hole-like center with spin 1/2 and principle g values g/sub zz/ = 2.045, g/sub xx/ = 1.995, g/sub yy/ = 2.004. The crystallographic orientation of the major axis of the g tensor is (a/sup ..-->../,b/sup ..-->../,c/sup ..-->../) = (.46, .16, .874). They identify this defect as an interstitial oxygen atom in the form of a peroxy radical; = Si - 0 - 0. The irradiation also produces an optical absorption band at 2 eV that displays a striking crystallographic anisotropy. The defect responsible for this band is unrelated to the peroxy, and appears to be diamagnetic. A tentative model is a doubly occupied dangling silicon bond. They will argue that this identification is likely to hold as well for the technologically important 2eV optical absorption band found in drawn glass fibers.
- Research Organization:
- Univ. of Missouri, Columbia
- OSTI ID:
- 6224431
- Journal Information:
- Appl. Phys. Commun.; (United States), Journal Name: Appl. Phys. Commun.; (United States) Vol. 7:1-2; ISSN APCOD
- Country of Publication:
- United States
- Language:
- English
Similar Records
Point defects in silicates
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Thesis/Dissertation
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Sat Dec 30 23:00:00 EST 1989
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OSTI ID:6288504
Related Subjects
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600* -- Radiation Chemistry
ABSORPTIVITY
ALUMINIUM COMPOUNDS
ALUMINIUM FLUORIDES
ALUMINIUM SILICATES
CHEMICAL RADIATION EFFECTS
CHEMISTRY
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DATA
ELECTRON SPIN RESONANCE
EXPERIMENTAL DATA
FIBERS
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
INFORMATION
INTERSTITIALS
MAGNETIC RESONANCE
NUMERICAL DATA
OPTICAL FIBERS
OPTICAL PROPERTIES
OXYGEN COMPOUNDS
PEROXY RADICALS
PHYSICAL PROPERTIES
PHYSICAL RADIATION EFFECTS
POINT DEFECTS
POLARIZATION
RADIATION CHEMISTRY
RADIATION EFFECTS
RADICALS
RESONANCE
SILICATES
SILICON COMPOUNDS
400600* -- Radiation Chemistry
ABSORPTIVITY
ALUMINIUM COMPOUNDS
ALUMINIUM FLUORIDES
ALUMINIUM SILICATES
CHEMICAL RADIATION EFFECTS
CHEMISTRY
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DATA
ELECTRON SPIN RESONANCE
EXPERIMENTAL DATA
FIBERS
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
INFORMATION
INTERSTITIALS
MAGNETIC RESONANCE
NUMERICAL DATA
OPTICAL FIBERS
OPTICAL PROPERTIES
OXYGEN COMPOUNDS
PEROXY RADICALS
PHYSICAL PROPERTIES
PHYSICAL RADIATION EFFECTS
POINT DEFECTS
POLARIZATION
RADIATION CHEMISTRY
RADIATION EFFECTS
RADICALS
RESONANCE
SILICATES
SILICON COMPOUNDS