EPR and ENDOR investigation of the (F/sub Li/)/sup 0/ center in CaO
A new paramagnetic color center, denoted by (F/sub Li/)/sup 0/, is reported. It has been observed in single crystals of CaO grown with lithium impurities. The center consists of a single electron in a O/sup 2 -/ vacancy with a Li/sup +/ ion replacing an adjacent Ca/sup 2 +/ ion, i.e., an F/sup +/ center next to a lithium substitutional impurity. Therefore, this is the first paramagnetic electron-defect center possessing local electrical neutrality to be seen in the alkaline-earth oxides. EPR and ENDOR measurements at both X and K band yield the following spin-Hamiltonian parameters at 4.2 K: g/sub parallel/=1.999 3(2); g/sub perpendicular/=2.000 1(2); A=minus-or-plus9.01(1) MHz; B=minus-or-plus5.35(1) MHz; and P< or =0.005 MHz. The hyperfine values are temperature dependent and are also reported for 77 and 150 K. The data suggest that there is an outward relaxation of the lithium ion and probably other ions in the lattice, but there is no electric-field gradient.
- Research Organization:
- Solid State Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830
- DOE Contract Number:
- W-7405-ENG-26
- OSTI ID:
- 6748303
- Journal Information:
- Phys. Rev., B: Condens. Matter; (United States), Journal Name: Phys. Rev., B: Condens. Matter; (United States) Vol. 23:1; ISSN PRBMD
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360603* -- Materials-- Properties
ALKALINE EARTH METAL COMPOUNDS
ANGULAR MOMENTUM
CALCIUM COMPOUNDS
CALCIUM OXIDES
CHALCOGENIDES
CHARGED PARTICLES
COLOR CENTERS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
ELECTRON SPIN RESONANCE
ENDOR
F CENTERS
HAMILTONIANS
HYPERFINE STRUCTURE
IONS
LITHIUM IONS
MAGNETIC RESONANCE
MATHEMATICAL OPERATORS
OXIDES
OXYGEN COMPOUNDS
PARTICLE PROPERTIES
POINT DEFECTS
QUANTUM OPERATORS
RESONANCE
SPIN
TEMPERATURE DEPENDENCE
VACANCIES