Fundamental absorption of Y/sub 2/O/sub 3/ and YAlO/sub 3/
The reflection spectra of Y/sub 2/O/sub 3/ and YAlO/sub 3/ crystals were determined in the photon energy range 4--14 eV. The Kramers--Kronig relationship was used to calculate the spectra of five optical characteristics: n, k, epsilon/sub 1/; epsilon/sub 2/, and the effective number of electrons N/sub eff/. Excitons of 6.0 eV energy and fapprox.0.1 oscillator strength were found for Y/sub 2/O/sub 3/, and the band gap of this material (approx. =6.1 eV) was determined. The origin and positions of the flat bands of Y/sub 2/O/sub 3/ were considered qualitatively and it was concluded that the interaction between the 5s and 4d states of the yttrium cations played an important role in the energy band structure. In the case of YAlO/sub 3/ only the beginning of the fundamental absorption region corresponding to h..nu..> or approx. =7.5 eV was studied. The composition dependence of the band gaps of the aluminates Y/sub x/Al/sub y/O/sub z/ was plotted.
- Research Organization:
- Institute of Physics, Academy of Sciences of the Estonian SSR, Tartu
- OSTI ID:
- 7094518
- Journal Information:
- Sov. Phys. - Solid State (Engl. Transl.); (United States), Journal Name: Sov. Phys. - Solid State (Engl. Transl.); (United States) Vol. 20:3; ISSN SPSSA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ABSORPTION
ALUMINATES
ALUMINIUM COMPOUNDS
CHALCOGENIDES
CORRELATIONS
ELECTRONIC STRUCTURE
ENERGY RANGE
EV RANGE
EV RANGE 01-10
EV RANGE 10-100
EXCITONS
KRAMERS-KRONIG CORRELATION
OSCILLATOR STRENGTHS
OXIDES
OXYGEN COMPOUNDS
QUASI PARTICLES
REFLECTION
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES