SiC在辐射场中的物理特性和光谱研究  

Molecular structure and spectrum of SiC under the radiation fields

作　　者：尹文怡 刘玉柱 张翔云 李炳生[2] 秦朝朝[3] 

机构地区：[1]南京信息工程大学物理与光电工程学院,南京210044 [2]中国科学院近代物理研究所,兰州730000 [3]河南师范大学物理与电子工程学院,新乡453007

出　　处：《原子与分子物理学报》2018年第1期1-6,共6页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(11475229;11304157);江苏省"六大人才高峰"高层次人才项目(2015-JNHB-011);南京信息工程大学大学生实践创新训练计划项目(201710300058Y)

摘　　要：本文采用密度泛函理论的B3LYP方法,在6-311G++(d,p)基组水平上优化了不同外电场(0-0.04a.u.)下碳化硅分子的基态稳定构型,在此基础上利用同样的方法计算了碳化硅分子的分子结构、偶极矩、总能量、能隙以及红外光谱、拉曼光谱、紫外-可见吸收光谱强度.结果表明,在外电场的作用下,分子结构变化明显,与电场呈现强烈的依赖关系.碳化硅分子键长一直在增大,电偶极矩先减小后增大,分子总能量先增大后减小,能隙E_G先减小后增大再减小再增大,红外光谱吸收峰出现红移现象,拉曼光谱出现蓝移现象.随着外电场的加强,分子紫外可见吸收光谱振子强度出现先增大后减小的反复变化,其波峰也出现蓝移现象.Based on the density functional theory DFT/B3LYP at 6 -311 ＋ ＋ g （d, p） level, the ground states of SiC molecule under different external electric fields are optimized. The influence of external electric field ran- ging from 0 to 0.04 a.u. on the geometrical parameters, dipole moment, total energy, energy gap, Infrared spectrum, Raman spectrum and UV -VIS absorption spectrum intensity are studied. The results show that the change of molecular structure is obvious, and it becomes strongly dependent on the field strength. The bond length of SiC molecular increases, the electric dipole moment is proved to be first decreasing, then increasing and the total molecular energy first increasing then decreasing. The energy gap of EG decreases firstly and then increases and then decreases again. The IR vibration spectrum of SiC molecule shows an observable red shift and the Raman vibration spectrum appears blue shift phenomenon. The oscillator strength of UV - VIS absorption spectrum is proved to be repeating the changes of the first increasing and then decreasing. The ultraviolet absorption peak is also blue - shifted with the increase of the field intensity.

关 键 词：SI C 辐射场 光谱 密度泛函理论 

分 类 号：O561.1[理学—原子与分子物理]