Karakalos Stavros, Siokou Angeliki, Dracopoulos Vasileios, Sutara Frantisek, Skala Tomas, Skoda Michal, Ladas Spyros, Prince Kevin, Matolin Vladimir, Chab Vladimir
Department of Chemical Engineering, University of Patras, Rion, Patras, Greece.
J Chem Phys. 2008 Mar 14;128(10):104705. doi: 10.1063/1.2888926.
Photoelectron spectroscopy with synchrotron radiation and low energy electron diffraction (LEED) were used in order to study the MgCl(2)Si(111) system. At submonolayer coverage of MgCl(2), a new LEED pattern was observed corresponding to a (sqr rt 3 x sqr rt 3)R30 degrees overlayer superimposed on the underlying reconstructed Si(111)7 x 7. The surface species at this stage are mainly molecular MgCl(2) and MgCl(x) (x<2) or MgO(x)Cl(y) attached to the Si substrate through Cl bridges coexisting with monodentate SiCl. The interfacial interaction becomes more pronounced when the submonolayer coverage is obtained by annealing thicker MgCl(2) layers, whereby desorption of molecular MgCl(2) is observed leaving on the nonreconstructed silicon surface an approximately 0.2 ML thick MgCl(x) layer which again forms the (sqr rt 3 x sqr rt 3 )R30 degrees superstructure.
为了研究MgCl₂/Si(111)体系，采用了同步辐射光电子能谱和低能电子衍射（LEED）技术。在MgCl₂的亚单层覆盖度下，观察到一种新的LEED图案，对应于叠加在底层重构的Si(111)7×7上的（√3×√3）R30°覆盖层。此阶段的表面物种主要是通过Cl桥连接到Si衬底上的分子MgCl₂和MgClₓ（x<2）或MgOₓClᵧ，它们与单齿SiCl共存。当通过对较厚的MgCl₂层进行退火获得亚单层覆盖度时，界面相互作用变得更加明显，此时观察到分子MgCl₂的解吸，在未重构的硅表面留下约0.2 ML厚的MgClₓ层，该层再次形成（√3×√3）R30°超结构。
