Phase Transformations and Photoluminescence Features of Gd2(1 – x)TbxEuxO3 Solid Solutions
| Autor: | T. D. Pivovarova, V. V. Bakovets, Mariana I. Rakhmanova, I. P. Dolgovesova |
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| Rok vydání: | 2020 |
| Předmět: |
010302 applied physics
Materials science Photoluminescence Infrared spectroscopy Crystal structure Condensed Matter Physics 01 natural sciences Electronic Optical and Magnetic Materials Crystallinity Phase (matter) 0103 physical sciences Physical chemistry 010306 general physics Monoclinic crystal system Solid solution Surface states |
| Zdroj: | Physics of the Solid State. 62:2412-2421 |
| ISSN: | 1090-6460 1063-7834 |
| Popis: | Solid solutions Gd2(1 – x)TbxEuxO3 (where x = 1 and 2.5 mol %) are prepared by the sol–gel method with subsequent annealing at 700–1200°C in air and hydrogen atmospheres. It is found by XRD and IR spectroscopy that the solutions undergo the chemical and phase transformations from the cubic modification to the monoclinic one in the annealing process and change the degree of crystallinity. Microinclusions of the Tb7O12:Eu3+ phase are present in a solid solution under certain annealing conditions, which are not formed in a hydrogen atmosphere or with a high activator concentration of 2.5 mol % at 1200°C. In accordance with these transformations, the Tb3+ and Eu3+ photoluminescence activators are redistributed over the C3i centrosymmetric and C2 noncentrosymmetric crystal lattice sites and the Cs surface states. These rearrangements give rise to changes in the parameters of the photoluminescence spectra, which are associated with a change in the ways of transferring the excitation energy of the main radiative transitions of the Tb3+ and Eu3+ photoluminescence activators. |
| Databáze: | OpenAIRE |
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