Glass samples in the GeO2 center dot SiO2 center dot Nb2O5 center dot K2O system, with different K2O/Nb2O5 ratios, were prepared, and glass-ceramics were obtained by controlled crystallization. Characterization included density measurements (Archimedes' method), differential thermal analysis, X-ray diffraction (XRD), and Raman and UV-Visible spectroscopies. Crystal volume fractions were estimated from density measurements, while XRD was used to estimate the crystal size, by the Scherrer formula. XRD and Raman data showed that a K2O/Nb2O5 ratio of 1 promoted the formation of the crystalline phase K3.8Nb5Ge3O20.4 and transparent glass-ceramics could be obtained with a crystalline fraction of 79 % and an average crystal size of 19 nm, while a K2O/Nb2O5 ratio of 2 promoted the formation of KNbO3 crystalline phase, and a translucent glass-ceramic was obtained with a crystalline fraction of 27 % and a crystal size of 14 nm. The Maker fringe method was used to compare the second-harmonic generation efficiency of the glass-ceramics with a Y-cut quartz reference.
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机译:制备GeO 2中心点SiO 2中心点Nb 2 O 5中心点K 2 O体系中具有不同K 2 O / Nb 2 O 5比率的玻璃样品,并通过控制结晶获得玻璃陶瓷。表征包括密度测量(Archimedes方法),差热分析,X射线衍射(XRD)以及拉曼光谱和紫外可见光谱。根据Sherrer公式,通过密度测量来估计晶体体积分数,而使用XRD来估计晶体尺寸。 XRD和拉曼数据表明,K2O / Nb2O5的比率为1可以促进结晶相K3.8Nb5Ge3O20.4的形成,可以获得透明的玻璃陶瓷,其晶体分数为79%,平均晶体尺寸为19 nm,而K 2 O / Nb 2 O 5的比率为2促进了KNbO 3晶相的形成,并且获得具有27%的晶体分数和14nm的晶体尺寸的半透明玻璃-陶瓷。使用Maker条纹法比较Y型切割石英玻璃的二次谐波产生效率。
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