cheminform abstract: crystallization of niobium germanosilicate glasses

ChemInform 2010, 41, issue 16 © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim www.cheminform.wiley-vch.de Glass V 1530 DOI: 10.1002/chin.201016212 Crystallization of Niobium Germanosilicate Glasses. — A series of glasses in the GeO2—SiO2—Nb2O5—K2O system are prepared by melting a mixture of K2CO3, Nb2O5, GeO2, and SiO2 (Pt crucibles, 1200—1450 °C, 50 min) and their characteristic temperatures are determined by DTA. Progressive replacement of GeO2 by SiO2 improves the thermal stability of the glasses. Nanocrystalline phases, KNbSi2O7, K 3 Nb 3 Si 2 O 13 , and K 3.8 Nb 5 Ge 3 O 20.4 related to the first exothermic peaks occur and are characterized by XRD and Raman spectroscopy. Transparent glass ceramics with a crystalline volume fraction of about 57% are obtained from the 40GeO2—10SiO2—25Nb2O5—25K2O (mol%) composition. Niobium germanosilicate glasses are potential candidates for the fabrication of transparent glass ceramics with interesting non-linear optical properties. — (SANTOS, R.; SANTOS*, L. F.; ALMEIDA, R. M.; DEUBNER, J.; WONDRACZEK, L.; J. Solid State Chem. 183 (2010) 1, 128-135; Dep. Eng. Mater., Inst. Super. Tec., Tech. Univ. Lisbon, P-1049 Lisboa, Port.; Eng.) — W. Pewestorf 16- 212

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Page 1: ChemInform Abstract: Crystallization of Niobium Germanosilicate Glasses

www.cheminform.wiley-vch.de

GlassV 1530 DOI: 10.1002/chin.201016212

Crystallization of Niobium Germanosilicate Glasses. — A series of glasses in the GeO2—SiO2—Nb2O5—K2O system are prepared by melting a mixture of K2CO3, Nb2O5, GeO2, and SiO2 (Pt crucibles, 1200—1450 °C, 50 min) and their characteristic temperatures are determined by DTA. Progressive replacement of GeO2 by SiO2 improves the thermal stability of the glasses. Nanocrystalline phases, KNbSi2O7, K3Nb3Si2O13, and K3.8Nb5Ge3O20.4 related to the first exothermic peaks occur and are characterized by XRD and Raman spectroscopy. Transparent glass ceramics with a crystalline volume fraction of about 57% are obtained from the 40GeO2—10SiO2—25Nb2O5—25K2O (mol%) composition. Niobium germanosilicate glasses are potential candidates for the fabrication of transparent glass ceramics with interesting non-linear optical properties. — (SANTOS, R.; SANTOS*, L. F.; ALMEIDA, R. M.; DEUBNER, J.; WONDRACZEK, L.; J. Solid State Chem. 183 (2010) 1, 128-135; Dep. Eng. Mater., Inst. Super. Tec., Tech. Univ. Lisbon, P-1049 Lisboa, Port.; Eng.) — W. Pewestorf

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