摘要
测定了亚碲酸铅玻璃的常温及高温Raman光谱。实验表明随着PbO浓度增大,亚碲酸盐玻璃中的四配位与三配位结构单元之间存在转化关系,体系总体非桥氧数增加。当加入的PbO摩尔浓度增大至50%后,四配位结构单元密度相对较少,这时玻璃结构中主要以三配位结构单元形式存在。同时还测定了40PbO·60TeO2玻璃的升温Raman光谱,观察到四配位结构单元桥氧、四配位结构单元非桥氧以及三配位结构单元非桥氧对称伸缩振动的谱峰由于温度升高引起的结晶化过程导致向高频移动,谱峰变得尖锐,强度增大。熔点后,Raman光谱出现展宽效应,强度降低。在玻璃处于熔化状态下,四配位中的微结构单元会进一步向三配位转化,熔体内部微结构单元含量会相对平衡。
Raman spectra of lead teUurite glasses and their melts were measured. Results show that four coordinate tellurite units convert into three coordinate units with increasing the concentration of PbO, and the number of non-bridging oxygen bonds （NBO） increases accordingly in this system. Three spectral peaks in the high frequency range were assigned to stretching vibration of bridging oxygen in four coordinate tellurite units （Qb）, stretching vibration of non-bridging oxygen in four coordinate tellurite units （Onb） and in three coordinate tellurite units （Tnb）. The relative density of four coordinate structure units decreases and the three coordinate tellurite units considerably exist in tellurite glasses when the concentration of PbO〉50%. Besides, the Raman frequencies of the three species＇ peaks become blue-shifted because of the temperature induced crystallization at high temperature, and the peak intensities increase and the peaks sharpen. The peaks merge together and become much broader while the glass is heated above the melting point because of multiple microstructure units coexisting.
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2008年第7期1564-1568,共5页
Spectroscopy and Spectral Analysis
基金
国家自然科学基金项目(50334040
40203001
50472104
50334050)资助
