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Previous issue date: 2016-04-15 / LaPO4:Eu3+/Tb3+ hierarquicamente nanoestruturados foram sintetizados por meio da atua??o combinada do aquecimento de micro-ondas e de um solvente bi-funcional (etileno glicol), que atua n?o somente como solvente, mas tamb?m como agente estabilizante. Foram preparadas cinco amostras com diferentes concentra-??es de eur?pio e t?rbio ? La0.93Eu0.07PO4, La0.93Tb0.07PO4, La0.93Eu0.006Tb0.064PO4, La0.93Eu0.011Tb0.059PO4, La0.93Eu0.017Tb0.053PO4 ? bem como a matriz pura. Estas amostras, na forma de p?, foram caracterizadas por Difra??o de Raios-X (DRX), Es-pectroscopia de Infravermelho com Transformada de Fourier por Reflet?ncia Total Atenuada (FTIR-ATR), Microscopia Eletr?nica de Transmiss?o (MET) e Fotolumi-nesc?ncia (PL). Os resultados indicam cristaliza??o com estrutura do tipo monazita monocl?nica. Tamb?m sugerem uma organiza??o hier?rquica de agregados de na-nopart?culas formadas por cristais de semente. As amostras codopadas exibiram luminesc?ncia azul autoativada da matriz hospedeira, assim como emiss?es verme-lha e verde oriundas os ?ons Eu3+ e Tb3+, respectivamente. A an?lise espectrosc?pi-ca sugere que a transfer?ncia de energia entre os ?ons ocorre do t?rbio para o eur?-pio, mas o inverso n?o foi observado. Al?m disso, a varia??o da concentra??o relati-va destes ?ons permitiu o controle de cor das emiss?es. Desta forma, podemos afir-mar que a rota sint?tica escolhida ? eficiente na prepara??o de nanomateriais com propriedades ?pticas avan?adas e potencial para aplica??es em fot?nica, sensoria-mento e biorotulagem. / Hierarchically Nanostructured LaPO4:Eu3+/Tb3+ powders were synthesized by the combined action of microwave heating and a bifunctional solvent (ethylene gly-col), which act as both, solvent and capping agent. Five samples were prepared with different amounts of europium and terbium - La0.93Eu0.07PO4, La0.93Tb0.07PO4, La0.93Eu0.006Tb0.064PO4, La0.93Eu0.011Tb0.059PO4, La0.93Eu0.017Tb0.053PO4 - and the pure matrix. These samples, in powder form, were characterized by X-ray Diffraction (XRD), Attenuated total reflectance Fourier transform infrared spectroscopy (FTIR-ATR), Transmission Electron Microscopy (TEM) and Photoluminescence (PL). The results indicate the crystallization structure of the monoclinic monazite type. Also suggests a hierarchical organization of nanoparticle aggregates formed by seed crys-tals. The co-doped samples exhibited self-activated blue luminescence of the host matrix, as well as red and green emissions from Eu3+ and Tb3+ions, respectively. The spectroscopic analysis suggests that the transfer of energy between the ions occurs from terbium to europium, but the opposite was not observed. Moreover, the variation of the relative concentration of these ions enabled the tuning emissions. Thus, we can say that the chosen synthetic route is efficient in the preparation of nanomateri-als with advanced optical properties and potential applications in photonics, sensing, and biolabeling.
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/21867 |
| Date | 15 April 2016 |
| Creators | Oliveira, Rosiv?nia Silva de |
| Contributors | 00735018405, http://lattes.cnpq.br/8938691250105531, Oliveira, Otom Anselmo de, 03936872449, http://lattes.cnpq.br/7903084274135177, Kulesza, Joanna Elzbieta, 70134641477, http://lattes.cnpq.br/1568423340359601, Barros, Braulio Silva |
| Publisher | PROGRAMA DE P?S-GRADUA??O EM QU?MICA, UFRN, Brasil |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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