• JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
 
  Bookmark and Share
 
 
Master's Dissertation
DOI
10.11606/D.3.2013.tde-11072014-093623
Document
Author
Full name
Shiva do Valle Camargo
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
São Paulo, 2013
Supervisor
Committee
Tatumi, Sonia Hatsue (President)
Mittani, Juan Carlos Ramírez
Santos Filho, Sebastião Gomes dos
Title in Portuguese
Confecção e caracterização de dosímetros luminescentes de cerâmicas de BaTiO3 nanoestruturadas.
Keywords in Portuguese
Dosimetria
Sol-Gel
Termoluminescência
Titanato de Bário
Abstract in Portuguese
Conforme pesquisas realizadas na literatura, o estudo do Titanato de Bário (BTO) na dosimetria é inédito, este material foi escolhido porque exibe propriedades luminescentes, demonstradas em experimentos de medidas de espectros de emissão. Para a confecção do BTO fez-se o uso da técnica química Sol-Gel, foi produzido amostras de BTO Puro, BTO dopado e co-dopado com diversas terras-raras. Todas as amostras produzidas sofreram calcinações com temperaturas definidas em 800, 1000 e 1200°C. As dopagens foram realizadas com os seguintes elementos terras-raras: Nd, Tb, Eu, Yb, Er, Pr, e as amostras co-dopadas foram com Tb/Eu e Yb/Er; no total foram confeccionadas trinta e uma amostras. No estudo de redução de massa foi constatada uma redução de metade das massas das amostras durante o processo de calcinação. Nas análises de Termoluminescência (TL) pelo menos uns dos tipos de calcinações apresentaram picos TL, com exceção das amostras co-dopadas com Tb/Eu. As amostras dopadas com Eu e Tb se destacaram nas análises das respostas termoluminescentes. A amostra com Tb e calcinada a 1200°C forneceu pico TL entre 90 a 200°C, e a dopada com Eu (1mol%) e calcinado a 1000°C apresentou picos TL em 110°C e 370°C. A mínima dose detectável para o pico de 110°C foi de 119 mGy e para o pico de 370°C foi de 143 mGy. As análises de MEV mostraram que as micrografias das amostras de BTO dopado tanto com Tb, quanto com Eu apresentaram superfícies porosas, diferentemente das Puras, que apresentaram superfície mais lisa. As análises de DRX indicaram uma fase tetragonal para as amostras Pura e dopadas com Eu (1 mol%), ambas calcinadas a 1000°C.
Title in English
Preparation and characterization of luminescent dosimeters nanostructured BaTiO3 ceramic.
Keywords in English
Barium Titanate
Dosimetry
Sol-Gel
Thermoluminescence
Abstract in English
According to the literature, the study of Barium Titanate (BTO) for dosimetry is unpublished yet, this material was chosen because it exhibits luminescent properties, demonstrated in emission spectra experiments. To make the BTO samples the chemical sol-gel technique was used. Samples of BTO Pure, doped and co-doped with different rare earths were made. All produced samples were calcinated with temperatures at 800, 1000 and 1200°C. The doping was performed with the following rare earths: Nd, Tb, Eu, Yb, Er, Pr, and some samples were co-doped with Tb / Eu and Yb / Er; in total were made thirty-one samples. In the study of weight reduction, a reduction, by half of the mass of raw material, was observed during the calcination process. In the TL analysis, at least one of the types (temperature) of calcinations provides TL peaks formation, except for the samples co-doped with Tb / Eu. The BTO: Eu and Tb provided the best TL response. The BTO: Tb and calcined at 1200°C showed TL peak at 90 to 200°C and the one doped with Eu (1mol%) and calcined at 1000°C supplied peaks at 110°C and 370°C. The minimum detectable dose to the TL peak at 110°C was 119 mGy and for TL peak at 370°C was 143 mGy. SEM analyzes showed that the micrographs of BTO samples doped with both Tb and Eu supplied porous surfaces, unlike the pure sample, that showed smoother surface. XRD analyzes indicated a tetragonal phase to pure sample and the one doped with Eu (1 mol%), both calcined at 1000°C.
 
WARNING - Viewing this document is conditioned on your acceptance of the following terms of use:
This document is only for private use for research and teaching activities. Reproduction for commercial use is forbidden. This rights cover the whole data about this document as well as its contents. Any uses or copies of this document in whole or in part must include the author's name.
Publishing Date
2014-07-14
 
WARNING: Learn what derived works are clicking here.
All rights of the thesis/dissertation are from the authors
Centro de Informática de São Carlos
Digital Library of Theses and Dissertations of USP. Copyright © 2001-2021. All rights reserved.