Luminescence and selective heat radiation of Yb2O3 upon the resonant and thermal laser excitation
| Autor: | L. D. Iskhakova, Alexander V. Kir'yanov, Nikita M. Karatun, Valery M. Mashinsky, V. M. Marchenko, E. M. Sholokhov |
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| Rok vydání: | 2012 |
| Předmět: |
Materials science
Laser diode business.industry Physics::Optics Stokes line Laser science Condensed Matter Physics Laser Molecular physics Industrial and Manufacturing Engineering Atomic and Molecular Physics and Optics law.invention Condensed Matter::Materials Science Optics law Condensed Matter::Superconductivity Melting point Crystallite Crystallization business Luminescence Instrumentation |
| Zdroj: | Laser Physics. 22:177-183 |
| ISSN: | 1555-6611 1054-660X |
| DOI: | 10.1134/s1054660x11240029 |
| Popis: | Yb2O3 polycrystals with a size of up to 10 mm are synthesized using the sintering and melting of the ultrapure Yb2O3 powders by the CO2-laser radiation with the power P L ≤ 100 W at the wavelength λ = 10.6 μm at the melting point T m = 2703 K, forming due to surface tension in melt, and crystallization in air. The analysis of the polycrystal microstructure using the methods of optical and electron microscopy and X- ray diffractometry shows that perfect oxide crystallites are formed in the course of crystallization after melting-through. The transformation of the luminescence and selective heat radiation (SHR) spectra of the Yb2O3 polycrystals is studied under the resonant excitation at λ ≈ 975 nm using a laser diode and the laser heating at the wavelength λ = 10.6 μm. When the resonant excitation power of the Yb3+ ions increases from 0.15 to 4.5 W, the Stokes luminescence of the Yb2O3 polycrystals is sequentially transformed into SHR and the thermal radiation of the crystal lattice. The transformation of the emission spectra of the Yb2O3 polycrystals with an increase in the laser heating intensity by about four orders of magnitude can be represented as the low-temperature heat radiation, spectral burst of the thermodynamically nonequilibrium SHR of the Yb3+ ions, and the high-temperature radiation of the crystal lattice. The temperature dependence of the luminescence spectra and SHR of the Yb2O3 polycrystals on the intensity of the laser and laser-thermal excitation and the concentration quenching of the Yb3+ luminescence in oxides indicate the key role of the interaction of the f-electron shell of the Yb3+ ions with the natural oscillations of the crystal lattice in the processes of the multiphonon excitation and nonradiative (multiphonon) and radiative (vibronic) relaxation. |
| Databáze: | OpenAIRE |
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