| Autor: |
NOVOSAD, S. S., NOVOSAD, I. S., BORDUN, O. M., KOSTYK, L. V., BORDUN, I. O., TUZYAK, O. YA. |
| Předmět: |
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| Zdroj: |
Acta Physica Polonica: A; Apr2018, Vol. 133 Issue 4, p806-810, 5p |
| Abstrakt: |
In this work the researched results of the spectral characteristics of the luminescence and the thermostimulated luminescence curves of Y2O3 and Y2O3:Eu ceramic materials at the X-ray excitation in the 85-295 K range were generalized. Considering the features of Y2O3 crystal structure and the possibility of the formation of the short-lived and stable hole and electron centers of V- and F-type by the ionizing radiation X-ray luminescence spectrum of ceramics at 85 K is fitted into the elementary Gaussian shape bands with the maxima near 3.40, 3.06, 2.67, 2.33, 2.09, and 1.91 eV. The main 3.40 and 3.06 eV bands of the luminescence are caused by the self-trapped excitons of (YO6)9- complex, when the cation is localized in the field of the trigonal (C3i) and monoclinic (C2) symmetries. The emission at 2.67 eV and the weak bands in the 1.65-2.61 eV region are considered as the radiation of excitons localized on the anion vacancies and the electron centers of F-type (F+, F and F-). The thermoluminescence of Y2O3 in the 186 and 204 K main peaks range is connected with the thermal destruction of the self-trapped states of O- ions that located in the field of the trigonal and monoclinic symmetries. The activator bands caused by 5D → 7Fj electronic transitions in Eu3+ are only observed in the X-ray and thermostimulated luminescence spectra of Y2O3:Eu ceramics. It was assumed that both at the X-rays irradiation and an optical excitation in the band of the charge transfer of Y2O3:Eu sample the energy goes to Eu3+ through (Eu2+O-) complexes (states) of the charge transfer. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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