Klemm Hagen W, Prieto Mauricio J, Xiong Feng, Hassine Ghada B, Heyde Markus, Menzel Dietrich, Sierka Marek, Schmidt Thomas, Freund Hans-Joachim
Fritz-Haber Institute of the Max-Planck Society, Faradayweg 4-6, 14195-, Berlin, Germany.
Department of Chemical Physics, University of Science and Technology of China, Hefei, 230026, P. R. China.
Angew Chem Int Ed Engl. 2020 Jun 22;59(26):10587-10593. doi: 10.1002/anie.202002514. Epub 2020 Apr 15.
The crystalline-to-vitreous phase transformation of a SiO bilayer supported on Ru(0001) was studied by time-dependent LEED, local XPS, and DFT calculations. The silica bilayer system has parallels to 3D silica glass and can be used to understand the mechanism of the disorder transition. DFT simulations show that the formation of a Stone-Wales-type of defect follows a complex mechanism, where the two layers show decoupled behavior in terms of chemical bond rearrangements. The calculated activation energy of the rate-determining step for the formation of a Stone-Wales-type of defect (4.3 eV) agrees with the experimental value. Charge transfer between SiO bilayer and Ru(0001) support lowers the activation energy for breaking the Si-O bond compared to the unsupported film. Pre-exponential factors obtained in UHV and in O atmospheres differ significantly, suggesting that the interfacial ORu underneath the SiO bilayer plays a role on how the disordering propagates within the film.
通过时间分辨低能电子衍射（LEED）、局域X射线光电子能谱（XPS）以及密度泛函理论（DFT）计算，研究了负载在Ru(0001)上的SiO双层膜的晶态到玻璃态的相变。该二氧化硅双层膜体系与三维二氧化硅玻璃具有相似性，可用于理解无序转变的机制。DFT模拟表明，斯通-威尔士（Stone-Wales）型缺陷的形成遵循复杂机制，其中两层在化学键重排方面表现出解耦行为。计算得到的形成斯通-威尔士型缺陷的速率决定步骤的活化能（4.3 eV）与实验值相符。与无支撑薄膜相比，SiO双层膜与Ru(0001)支撑体之间的电荷转移降低了破坏Si-O键的活化能。在超高真空（UHV）和氧气气氛中获得的指前因子有显著差异，这表明SiO双层膜下方的界面氧原子对无序在薄膜内的传播方式有影响。
