标题：Microstructural evolution of transparent glass-ceramics containing CO2+: MgAl2O4 nanocrystals
作者：Duan, XL; Yuan, DR; Luan, C; Sun, ZH; Xu, D; Lv, MK
作者机构：[Duan, XL; Yuan, DR; Luan, C; Sun, ZH; Xu, D; Lv, MK]Shandong Univ, State Key Lab Crystal Mat, Jinan 250100, Peoples R China.
通讯作者地址：[Duan, XL]Shandong Univ, State Key Lab Crystal Mat, Jinan 250100, Peoples R China.
来源：JOURNAL OF NON-CRYSTALLINE SOLIDS
摘要：Transparent glass-ceramics containing Co2+: MgAl2O4 nanocrystals were obtained by the sol-gel process. The gels with composition of 4.9MgO-5.9Al(2)O(3)-89SiO(2)-0.2CoO (mol%) (MAS) were prepared at room temperature, and heat-treated at different temperatures. The structural evolution of the samples was studied with X-ray diffraction (XRD) and infrared spectra. Co2+: MgAl2O4 nanocrystals were precipitated from the MAS system and dispersed in the SiO2-based glass when the sample was heated at 1000 degreesC. Optical absorption spectra showed that Co2+ ions were located in tetrahedral sites replacing Mg2+ ions in MgAl2O4 nanocrystals. TEM revealed spherical nanocrystals of the size of about 5-15 nm, depending on the heat-treatment temperature. The Co2+: MgAl2O4 nanocrystals in the amorphous silica matrix proved to be very stable up to 1100 degreesC without any decomposition. (C) 2003 Elsevier B.V. All rights reserved.