Influence of sintering temperature on defects in porous silica monoliths studied by positron annihilation techniques

摘要：

Positron lifetime and coincidence Doppler broadening spectra for porous silica calcined at temperatures from 900 to 1500 ℃ have been measured. As the sintering temperatures increasing from 900 to 1000 ℃, the height of the peaks of the ratio curves decrease, and the τ3 increases, which is due to the exclusion of the gas and the organic substance out of the cavities. As the sintering temperatures increasing from 1000 to 1250 ℃, some of the defects were recovered, the grains of low quarts appearing and growing. This gives rise to the increase of the height of the peak of the ratio curve, and the decrease of lifetime (τ1,τ2 and τ3). As the sintering temperatures increasing from 1250 to 1500℃, the height of the peak of the ratio curve decreases, and the lifetime increases due to the phase transition of low quartz to cristobalite.

关键词： Silica defect sintering temperature positron annihilation

作者: Huang Yu-Yang Xiong Chao Wang Yu-Xin Lu Yan-Qiong Deng Wen

作者单位: Department of Physics,Guangxi University,Nanning 530004,P.R.China

会议类型: 国际会议

会议名称: 第九届国际正电子与正电子素国际会议(9th International Workshop on Positron and Positronium Chemistry)(PPC–9)

会议地点: 武汉

会议语种:英文

页码: 204-206

在线出版日期: 2008-05-11（万方平台首次上网日期，不代表论文的发表时间）