FORTH/ICE-HT, P.O. Box 1414, GR-26504 Rion, Patras, Greece.
J Chem Phys. 2012 Jun 14;136(22):224703. doi: 10.1063/1.4727760.
Photoelectron spectroscopy with synchrotron radiation, low energy electron diffraction, and ion-scattering spectroscopy were used in order to study the Ti/MgCl(2) interface grown on an atomically clean Si(111) 7 × 7 substrate. A series of high resolution spectra after deposition of a thick MgCl(2) layer, step by step deposition of Ti and gradual annealing, indicated a very reactive interface even at room temperature. Strong interaction between the incoming Ti atoms and the MgCl(2) layer, leads to the formation of Ti(2+) and Ti(4+) oxidation states. The interfacial interaction continues even at multilayer Ti coverage mainly by the partial disruption of Mg-Cl bonds and the formation of Ti-Cl sites, rendering this interface a very promising UHV-compatible model of a pre-catalyst for olefin polymerization. After the final annealing, the MgCl(2) multilayers desorb while Ti remains on the surface forming a silicide layer on which Cl and Mg atoms are attached.
采用同步辐射光电电子能谱、低能电子衍射和离子散射谱学，研究了原子级清洁 Si(111) 7×7 衬底上生长的 Ti/MgCl(2)界面。在沉积厚 MgCl(2)层后、逐步沉积 Ti 和逐步退火后获得的一系列高分辨率谱表明，即使在室温下，界面也具有很强的反应性。进入的 Ti 原子与 MgCl(2)层之间的强烈相互作用导致 Ti(2+)和 Ti(4+)氧化态的形成。界面相互作用甚至在多层 Ti 覆盖时仍在继续，主要是通过部分破坏 Mg-Cl 键并形成 Ti-Cl 位，使该界面成为一种很有前途的 UHV 相容的前催化剂模型，适用于烯烃聚合。最后退火后，MgCl(2)多层解吸，而 Ti 留在表面上，形成一个硅化物层，其上附着着 Cl 和 Mg 原子。
