同步辐射技术和透射电镜技术以及密度泛函理论相结合的综合表征方法及其应用

同步辐射技术和透射电镜技术是研究材料的重要表征手段,广泛应用于物理、化学、材料、环境与能源等学科的前沿研究领域.这两种技术方法,其物理原理是光子和电子与材料的相互作用,包括光子在材料中的散射与吸收,电子的衍射与能量损失等,从而演化出各种具体表征手段.从物理本质看,基于量子力学的密度泛函理论,其本征函数可以与同步辐射X射线的衍射和透射电镜电子的衍射得到的电荷密度相对应,而其本征值则可以与同步辐射X射线的吸收谱和光电子谱以及透射电镜电子的能量损失谱得到的能级或能带信息相对应.这些对应关系使得这两种技术手段和理论计算方法可以互相验证也可以互相补充,从而对材料的结构和电子信息的分析更为全面细致.本文综述了同步辐射技术和透射电镜技术的进展,通过典型材料表征进行举例说明,这两种技术结合密度泛函理论,能够深入分析功能材料的晶体结构信息以及各种物理化学性能.最后展望了这三种方法相结合的未来发展趋势.

Principles and applications of a comprehensive characterization method combining synchrotron radiation technology,transmission electron microscopy,and density functional theory

Synchrotron radiation and transmission electron microscopy(TEM)technologies are important characterization methods of materials and are widely used in the frontier research fields of physics,chemistry,materials,environment,and energy.Both methods exploit the interaction of photons and electrons with materials,including the scattering and absorption of photons in the material and the diffraction and energy loss of electrons.Through these techniques,various specific characterization methods have evolved.In the density functional theory(DFT)which is based on quantum mechanics,the eigenfunction can be related to the charge density obtained from the synchrotron radiation X-rays diffraction and electron diffraction in TEMs,and the eigenvalue corresponds to the energy level or band structure obtained from the photoelectron emission spectra/absorption spectra of synchrotron radiation and the electron energy loss spectra of TEM.With these corresponding relations,the two techniques and theoretical calculations can verify and/or complement each other,providing detailed analyses of the structure and electronic information of materials.This article reviews the progress of synchrotron radiation and transmission electron microscopy technologies and their applications to typical material characterization.The article emphasizes how the spatial and temporal resolutions of both technologies have advanced through nanotechnology and quantum mechanics developments.Such cutting-edge technology will promote the discovery of new functional materials.