本文以耦合的Au纳米双颗粒以及Au/Cd S核壳双颗粒为例,介绍了利用有限元多物理场耦合软件COMSOL计算电子能量损失谱的方法。计算结果不仅证实了实验中观察到的共振吸收峰随电子束入射点远离颗粒而红移的结果,也揭示出高能电子所激发的振荡模式和系统本征模式之间的差异,表明所获取的电子能量损失谱的振荡模式并非是单一的本征振荡,而是几种本征模式组合而成的混合模式。
The surface plasmon vibration in electron energy loss spectrum (EELS) was simulated for the coupled Au dimer and A〇/ CdS dimer with COMSOL software. The simulated spectrum reproduces the red shift of the absorption peaks when the electron beam moves away from the dimers. Moreover, the electric field modes induced by the incident electron beam are different with any eigenmode of the dimers, implying that the electron beam invokes the mixed surface vibration modes.