Silva, Maurício A.P. [UNESP]Messaddeq, Younes [UNESP]Briois, ValeriePoulain, MarcelRibeiro, Sidney José Lima [UNESP]2014-05-202014-05-202002-01-01Journal of the Brazilian Chemical Society. Sociedade Brasileira de Química, v. 13, n. 2, p. 200-206, 2002.0103-5053http://hdl.handle.net/11449/29130A partir de resultados de experimentos de fusão e choque térmico, o domínio vítreo foi identificado no sistema PbF2-CdF2-B2O 3. Vidros puros e dopados com Er3+ foram preparados e vitrocerâmicas foram obtidas a partir de tratamentos térmicos adequados. A fase cristalina foi identificada como beta-PbF2. Estudos estruturais foram efetuados por difração e absorção de raios X e o papel desempenhado pelos átomos de Pb2+ e Cd2+ na estrutura vítrea foi estabelecido a partir destas técnicas. Os resultados sugerem que, com a cristalização, os íons Er3+ são segregados na fase cristalina.The vitreous domain was established in the PbF2-CdF2-B2O 3 system from melting and quenching experiments. Er3+ containing glasses were prepared and glass ceramics were obtained by selected heat-treatments. Lead fluoride was identified (beta-PbF2) as the crystalline phase. Structural studies were performed in some glassy and partially crystallized samples by means of X-ray Diffraction (XRD) and Extended X-ray Absorption Fine Structure (EXAFS) measurements. The role of Cd2+ and Pb2+ atoms on the glass network formation and also on the crystallization behavior was put forward by these techniques. After crystallization Er3+ atoms segregated in the crystal phase.200-206engoxifluoride glassesglass-ceramicsx-ray absorption spectroscopyArtigo10.1590/S0103-50532002000200011S0103-50532002000200011Acesso abertoS0103-50532002000200011.pdf299850384191781564460474630346540000-0003-3286-9440