材料科学与工程学报2025，Vol.43Issue(6)：940-945,6.DOI:10.14136/j.cnki.issn1673-2812.2025.06.009
22NaCl源对有序介孔二氧化硅辐照效应的正电子湮没
Positron Annihilation Study of Ordered Mesoporous Silica Irradiated by 22NaCl Source
摘要
Abstract
With the emergence of controllable ordered mesoporous silica,its research and application fields have been further expanded.In this paper,ordered mesoporous silica was synthesized by hydrothermal synthesis,and its positron annihilation lifetime(PAL)and doppler broadening(DB)spectra were tested.The irradiation effect of 22NaCl positron source in ordered mesoporous silica SBA-15 and the interaction between temperature and irradiation effect were studied.SBA-15 samples were placed in a vacuum chamber at a pressure of approximately 10-6 Torr and cooled to 10 K with a closed cycle helium refrigerator.PAL and DB tests were performed for 60 h irradiation at 10 K and a heating process of 10-300 K/10 K.The results indicate that during the irradiation process,the long-life components significantly decrease and the S parameter significantly increases.This may be due to the irradiation of positron source generates a large number of paramagnetic centers on the grain surface of SBA-15,leading to the spin quenching of positronium.The radiation-induced paramagnetic center is the dominant factor below 50 K,and the positron lifetime spectrum is almost the same as before,while the temperature rises to 110 K.A medium life component of about 9 ns appeared after irradiation,and its intensity increased with the increase of irradiation time,possibly due to the formation of surface state positronium(o-Ps).关键词
SBA-15/正电子湮没/电子偶素/低温辐照Key words
SBA-15/Positron annihilation/Positronium/Low temperature irradiation分类
化学化工引用本文复制引用
宋小勇,杨睿宁,吴雪莹,薛永生..22NaCl源对有序介孔二氧化硅辐照效应的正电子湮没[J].材料科学与工程学报,2025,43(6):940-945,6.基金项目
国家自然科学青年基金项目(12205100,11805295) （12205100,11805295）
河南省高等学校重点科研项目(23B140002) （23B140002）
