摘要
以组成为n(SiO_2)∶n(Al2O3)∶n(CaO)∶n(CaF_2)∶n(NaF)∶n(B_2O_3)=40∶20∶10∶10∶15∶5的微晶发光玻璃为基质,采用一步析晶法制备了CaF_2析晶相.利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、X射线能量散射谱仪(EDS)和荧光分光光度计等对样品结构、组成及光谱性能进行分析,探讨了Eu3+掺杂浓度和析晶温度对微晶玻璃发光性能的影响.实验结果表明,在850℃下处理可获得分布均匀、粒径尺寸为200 nm的CaF_2析晶相,微晶玻璃的发光强度是基质玻璃的1.7倍.微晶玻璃的发射光谱在590,614,652和700 nm出现发射峰,分别对应Eu3+的5D0-7FJ(J=1,2,3,4)跃迁.通过对5D0-7F1和5D0-7F2跃迁强度的分析以及Judd-Ofelt理论参数Ω2值的计算可知Eu3+周围晶体场在析晶前后对称性发生变化.机理分析表明,析晶处理后Eu3+从高声子能量的Si-O环境进入低声子能量的Ca-F环境中,说明Eu3+可作为荧光探针研究微晶玻璃晶体结构的变化.
Transparent glass-ceramics with composition n（ SiO2） ∶ n（ Al2O3） ∶ n（ CaO） ∶ n（ CaF2） ∶ n（ NaF） ∶n（ B2O3） = 40∶ 20∶ 10∶ 10∶ 15∶ 5 were fabricated via traditional melting technique with one-step method.X-ray diffraction（ XRD） results of as-prepared glass-ceramics confirmed the existence of CaF2 phase. Scanning electron microscopy（ SEM） observation showed that the CaF2 crystalline phase had a size of 200 nm and dispersed in the amorphous phase. The fluorescence intensity of glass ceramics was 1. 7 times that of the glass.The emission spectrum showed several luminescence peaks at 590 nm（^5D0→^7F1）,614 nm（^5D0→^7F2）,652nm（^5D0→^7F3） and 700 nm（^5D0→^7F4）,which are attributed to the Eu^3＋ion transition. The intensity ratio of ^5D0-^7F2 transition to the ^5D0-^7F1 transition and Ω2of Judd-Ofelt parameters were used to measure the rare earth ion site symmetry. The data revealed that Eu^3＋ ions are embedded into Ca-F environment from Si-O environment during the crystallization process. Therefore Eu^3＋ can be applied to investigate the microstructures of glass-ceramic crystal as a fluorescence probe.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2016年第4期607-612,共6页
Chemical Journal of Chinese Universities
基金
国家自然科学基金(批准号:51372012)资助~~
关键词
微晶玻璃
荧光探针
发射光谱
局域环境
Glass ceramic
Fluorescence probe
Emission spectrum
Local environment
