纳米CeO_2键弛豫动力学的计量拉曼谱分析

Quantitative Raman Spectrum Analysis of Nanoparticle CeO_2 Bond Relaxation

纳米CeO2的原子结构变化和键弛豫作用决定了其应用领域.从化学键弛豫及振动的角度出发,利用声子计量谱学技术,探讨拉曼光谱压强效应背后的物理机制.应用键弛豫理论,对纳米CeO2的拉曼光谱压强效应进行定量分析;建立声子谱与压强的函数关系,求取体模量和压缩系数;阐述纳米CeO2拉曼频移蓝移的物理起因,即压强增大促使CeO2键长收缩、键能增强,引起拉曼谱发生蓝移现象.

The atomic structure and bond relaxation of Nanoparticle CeO2 determine its applications.From the perspective of chemical bonds relaxation and vibration,and with phonons spectroscopy measurement technique,the physical mechanism of the Raman spectrum pressure effect is explored.Based on the theory of bond relaxation,the Raman spectrum pressure effect of nanoparticle CeO2 is quantitatively analyzed.The functional relationship between phonon spectrum and pressure is established.At the same time,the bulk modulus and compressibility coefficient are evaluated.The physical causes of Raman frequency-shift and blue-shift of CeO2 are explored,and it is found that pressure increase prompts contraction of bond length and bond energy enhancement leads to blue-shift of Raman spectrum.