Desenvolvimento e caracterização fototérmica de novos materiais vítreos dopados com íons emissores terras-raras

Detalhes bibliográficos
Ano de defesa: 2009
Autor(a) principal: Martins, Vanessa Menezes
Orientador(a): Não Informado pela instituição
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Federal de Uberlândia
Brasil
Programa de Pós-graduação em Física
Programa de Pós-Graduação: Não Informado pela instituição
Departamento: Não Informado pela instituição
País: Não Informado pela instituição
Palavras-chave em Português:
Link de acesso: https://repositorio.ufu.br/handle/123456789/19674
Resumo: In this work two new glass matrices has been developed, a phosphate and borate one, PAN (40P2O5.20 Al2O3. 40Na2CO3 (mol%)) and BAN (40B2O3. 20 M2O3. 40Na2CO3 (mol%)), namely. The matrices were doped with increasing concentration of neodimium and praseodymium rare-earth ions in order to study its thermal and optical properties. To obtain these properties, initially, measurements of optical absorption, photoluminescence, lifetime, refractive index, mass density and specific heat were performed. In addition, applying the time resolved mode mismatched dual beam thermal lens technique the thermal-optical properties were found. It was found that the PAN and BAN thermal diffusivities were quite similar. By using a reference sample the quantum efficiency of the neodymium sample were determined. It was noticed that the insertion of dopant fens causes a luminescence quenching. This effect became more evident in the decreasing of the quantum efficiency (and lifetime) when concentration is increased. Finally, from the above results it was possible to calculate the nonradiative relaxation rate. All the found results were analised as a function of concentration. In particular, the PAN matrix presents a good combination of thermal and optical properties, which are essential to possible aplication in optical devices.