Structure and vibrational spectra of crystalline SiO2 ultra-thin films on Mo(112)

被引：60

作者：

Giordano, L

Ricci, D

Pacchioni, G

Ugliengo, P

机构：

[1] Univ Milan, Dipartimento Sci Mat, I-20125 Milan, Italy

[2] Univ Turin, IFM, Dipartimento Chim, I-10125 Turin, Italy

[3] NIS, Nanostructured Interfaces & Surfaces Ctr Excellen, I-10125 Turin, Italy

来源：

SURFACE SCIENCE | 2005年 / 584卷 / 2-3期

关键词：

oxide films; vibrational spectra; SiO2; Mo(112); DFT calculations;

D O I：

10.1016/j.susc.2005.03.060

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The structure and the vibrational properties of ultra-thin SiO2 films (one to three layers, 1-3 L) epitaxially grown on a Mo(112) substrate have been determined by first principle DFT calculations. For 2 L and 3 L films the structures considered are derived from those of beta-cristobalite, beta-tridymite, alpha- or beta-quartz; for 1 L films we considered regular arrays of isolated SiO4 tetrahedra, one-dimensional (SiO3)(n) chains, or an hexagonal two-dimensional (SiO2.5) structure. The 1 L films have the c(2 x 2) pattern observed experimentally. On the basis of the comparison of the computed frequencies with IR and HREEL spectra, of the existing data on film thickness, periodicity, and surface reactivity, we conclude that the film consists of a single silica layer with hexagonal c(2 x 2) structure. (c) 2005 Elsevier B.V. All rights reserved.

引用

页码：225 / 236

页数：12