ESTUDO DE FASES E CRESCIMENTO DE MONOCRISTAIS NO SISTEMA Bi2O3 - TiO2 - ZrO2
I n this work a systematic study on the phase formation and stability in the system Bi2O3-ZrO2 was realized, the solubility of the Zr4+ ion in Bi12TiO20 (BTO) was investigated and Zr-doped BTO crystals (BTO:Zr) were grown and optically characterized. It was verified that a tetragonal phase was forme...
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| Format: | master thesis |
| Status: | Published version |
| Publication Date: | 2008 |
| Country: | Brasil |
| Institution: | Universidade Federal de Goiás (UFG) |
| Repository: | Repositório Institucional da UFG |
| Language: | Portuguese |
| OAI Identifier: | oai:repositorio.bc.ufg.br:tde/1044 |
| Online Access: | http://repositorio.bc.ufg.br/tede/handle/tde/1044 |
| Access Level: | Open access |
| Keyword: | crescimento de cristais cristais fotorrefrativos síntese no estado sólido Bi2O3 - TiO2 - ZrO2 CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
| Summary: | I n this work a systematic study on the phase formation and stability in the system Bi2O3-ZrO2 was realized, the solubility of the Zr4+ ion in Bi12TiO20 (BTO) was investigated and Zr-doped BTO crystals (BTO:Zr) were grown and optically characterized. It was verified that a tetragonal phase was formed in the following wide composition interval: (6-x)Bi2O3:(1+x)ZrO2, with x = 0.5, 0.3, 0.2, 0.1, 0, -0.1, -0.2, -0.3, -0.5, -0.65 e -0.7. The phases were synthesized by solid state reaction and the powders were characterized by Xray diffraction and diferential thermal analysis. The formed tetragonal phase, however, was metastable for all investigated compositions and its preparation was dependent on the sample thermal history. The stable phase at room temperature was a monoclinic one. A low solubility of Zr4+ in BTO was verified, but BTO:Zr single crystals were grown by Top Seeded Solution Growth (TSSG) technique. Good quality crystalline samples were prepared and characterized by chemical compositon and by optical activity, photoconductivity and electro-optical measurements. The results shown that Zr-doping produced a decreasing in the crystal photosensitivity, and almost no changes in the optical activity and electro-optical coefficient were generated. |
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