Poirier, GaelCassanjes, Fabia C.Messaddeq, Younes [UNESP]Ribeiro, Sidney José Lima [UNESP]2014-05-202014-05-202009-03-15Journal of Non-crystalline Solids. Amsterdam: Elsevier B.V., v. 355, n. 7, p. 441-446, 2009.0022-3093http://hdl.handle.net/11449/26139Tungstate fluorophosphate glass compositions with high WO3 concentration were prepared in the ternary system (80-0.8x)NaPO3-(20-0.2x)BaF2-xWO(3) with x = 40,50 and 60 mol%. Transparency decreases as WO3 concentration increases but can be improved by addition of oxidizing systems such as CeO2 or Sb2O3/NaNO3. Characterizations by thermal analysis (DSC) point out that an increase in the amount of WO3 results in a higher glass transition temperature. In addition, such compositions are very stable against devitrification since samples containing 40% and 50% of WO3 donot even exhibit the expected crystallization event. In these samples, the stability against crystallization decreases with the WO3 content and vitreous sample containing 60% of WO3 exhibits an endothermic event around 620 degrees C due to crystallization of monoclinic WO3 phase. In these glasses, it was shown that the nucleation stage can be induced by thermal-treatment when external nucleating agents such as Ti or Sb are used. Finally, gold-doped samples exhibit a higher crystallization tendency and monoclinic WO3 phase can be grown in such glasses. (C) 2009 Elsevier B.V. All rights reserved.441-446engGlass-ceramicsX-ray diffractionPhosphatesArtigo10.1016/j.jnoncrysol.2009.01.008WOS:000264963000008Acesso restrito299850384191781564460474630346540000-0003-3286-9440