表面吸附和反应过程的近边X射线吸收精细结构模型研究

EXAFS (Near-edge X-rays absorption fine structure) is a reliable method instudying the atomic and electronic structure of the condensed matter, especially forthe disorder system, in which it has been identified as the "fingerprint analysis" of the local structure, and exhibitsitself a high precision.During the urfaceadsorption and reaction process, the dynamic varieties of the electronic state and local atomic structure for adsorbate and substrate are unveiled bythe NEXAFS studies. With the high-speed development of synchrotron radiation technique, the NEXAFS study in condensed matter structure has shown itself a more important method..In our present project, we mainly utilize the MSC(Multiple-scattering cluster) and self-consistent field DV-Xα methods to approach the NEXAFS spectra for a series of adsorption systems, and obtain their atomic structures and electronic states information. As for the SO2/Ni(111) system, our MSC calculation shows that it is the η3 configuration. The preferable adsorption site for S atom is fcc hollow site while two O atoms locate in the vicinity of the atop site. The investigation modifies the conclusion of previous Japanese and English scholars. The structure of SO2/Pd(111) is traditional η2 configuration. Moreover, In the room temperature SO2 is decomposed to SO+O and SO3 respectively on the Cu(100) and Cu(111) surface. Our MSC calculation associated with DV-Xα method confirms the conclusion. The works initiate a potential method in NEXAFS study, which closely connects the atomic structure and electronic tate.Furthermore, our study confirms the self-assembly structure of Cl-passivated Ge(111) surface, which provides an effective method for the MSA(molecular self-assembly) investigation, the 21-century profitable and intriguing technology. In the past three years, our group implements the project research plan, and has published 16 papers in the SCI and EI magazines. Moreover, four Ph.D candidates have been rewarded their degree.

以乙炔/Si（111）和二氧化硫/Ni(110)等表面吸附系统为例，构造这些系统在热退火条件下各种可能的结构模型，利用近边X射线吸附精细结构（NEXAFS）的多重散射团簇方法（MSC）计算与这些模型对应的NEXAFS谱，与实验比较实现对表面反应过程的实时原位模拟监测，⑶蟮帽砻娼峁埂