摘要
为研究辐照缺陷产生及其热稳定性,对SiC晶体实施了不同通量中子辐照。利用高分辨X射线衍射和单晶X射线衍射研究了中子辐照6H-SiC晶体的肿胀效应以及退火对肿胀的回复作用。研究结果表明,SiC晶体经中子辐照后产生的主要缺陷是点缺陷,中子辐照通量越大,SiC晶体肿胀效应越显著。在2.85×1024n/m2辐照通量下,SiC晶体未出现非晶化。高温退火可使肿胀的SiC晶格回复,1450℃退火275 min晶胞参数回复至辐照前水平。退火过程晶胞体积回复符合一级反应方程,利用等温退火方法计算分析迁移能分布。实验发现不同缺陷迁移能分别对应不同退火温度阶段:0.16 eV对应200~500℃退火;0.24 eV对应600~1100℃退火;1.15 eV对应1200~1400℃退火。200~500℃温度区间主要是C的Frenkel缺陷复合;600~1100℃温度区间主要是Si的Frenkel缺陷复合;更高温度区间1200~1400℃则对应C、Si间隙原子复合。实验结论对全面掌握晶体测温技术、提高测温精度具有一定的指导意义。
To evaluate neutron irradiation induced crystalline defects and its thermal stability,the single crystal SiC specimens are neutron irradiated with different fluences. The effects of irradiation swelling and the recovery behavior of post-irradiation SiC by the annealing were studied by means of high-resolution X-ray diffraction,single crystal X-ray diffraction and so on. The results show that the main defect induced into crystalline lattice is point defect,and the lattice expansion increases with the increasing of neutron irradiation fluence. The Si C specimens were irradiated up to a fluence of 2. 85 × 1024 n/m2,and amorphization did not occur. The lattice parameters of post-irradiation specimens were recovered with isothermal annealing up to 275 min at 1450 ℃ . The calculation of activation energies,obtained from precise crystal cell volume measurement during each isothermal annealing step,revealed that volume recovery behavior between 200 ℃ and 1400 ℃ could almost be explained by a first order reaction,and it was found there were three stages with different activation energies. The activation energy of SiC was 0. 16 eV at 200 ~ 500 ℃,0. 24 eV at 600 ~ 1100 ℃,1. 15 eV at 1200 ~ 1400 ℃,respectively. Below 1100 ℃,the recombination occurred possibly for closely positioned C and Si Frenkel pairs. In addition,at 1200 ~ 1400 ℃,recombination of C and Si interstitials may have occurred for Si C specimens. The experimental results have a certain guiding significance for mastering the crystal temperature sensing technology and improving the temperature measurement accuracy.
作者
李欣
梁晓波
高云端
黄漫国
崔晓红
张守超
LI Xin;LIANG Xiao-bo;GAO Yun-duan;HUANG Man-guo;CUI Xiao-hong;ZHANG Shou-chao(AVIC Beijing Changcheng Aeronautic Measurement and Control Technology Research Institute,Beijing 101111,China;Aviation Key Laboratory of Science and Technology on Special Condition Monitoring Sensor Technology,Beijing 101111,China;School of Science,Tianjin Chengjian University,Tianjin 300384,China)
出处
《测控技术》
2021年第3期28-33,共6页
Measurement & Control Technology
基金
航空科学基金项目(2018ZD34001,201834Y2001)
天津市科技支撑计划项目(19JCTPJC47800)
天津市高等学校基本科研业务费资助(2016CJ18)。
关键词
退火温度
退火时间
晶格回复
缺陷迁移能
晶体温度传感器
annealing temperature
annealing time
lattice recovery
activation energy
crystal temperature sensor
