Department of Physics, Ritsumeikan University, Kusatsu, Shiga-ken 525-8577, Japan.
J Chem Phys. 2013 Jun 28;138(24):244705. doi: 10.1063/1.4811485.
High-resolution medium energy ion scattering (MEIS) spectrometry coupled with photoelectron spectroscopy revealed unambiguously that the initial SrTiO3(001) surface chemically etched in a buffered NH4F-HF solution was perfectly terminated with a single-layer (SL) of TiO2(001) and annealing the surface at 600-800 [ordinal indicator, masculine]C in ultrahigh vacuum (UHV) led to a (2 × 1)-reconstructed surface terminated with a double-layer (DL) of TiO2(001). After annealing in UHV, rock-salt SrO(001) clusters with two atomic layer height grew epitaxially on the DL-TiO2(001)-2 × 1 surface with a coverage of 20%-30%. High-resolution MEIS in connection with ab initio calculations demonstrated the structure of the DL-TiO2(001)-2 × 1 surface close to that proposed by Erdman et al. [Nature (London) 419, 55 (2002)] rather than that predicted by Herger et al. [Phys. Rev. Lett. 98, 076102 (2007)]. Based on the MEIS analysis combined with the ab initio calculations, we propose the most probable (2 × 1) surface structure.
高分辨率中能离子散射（MEIS）光谱学与光电子能谱学的结合明确表明，在缓冲的 NH4F-HF 溶液中化学刻蚀的初始 SrTiO3(001) 表面完美地终止于单层（SL）的 TiO2(001)，并且在超高真空（UHV）中在 600-800°C 下退火导致具有双层（DL）的 TiO2(001)终止的（2×1）重构表面。在 UHV 中退火后，具有两个原子层高度的岩盐 SrO(001) 团簇在 DL-TiO2(001)-2×1 表面上外延生长，覆盖率为 20%-30%。高分辨率 MEIS 与从头计算相结合证明了 DL-TiO2(001)-2×1 表面的结构接近于 Erdman 等人提出的结构[Nature（London）419, 55 (2002)]，而不是 Herger 等人预测的结构[Phys. Rev. Lett. 98, 076102 (2007)]。基于 MEIS 分析与从头计算相结合，我们提出了最可能的（2×1）表面结构。
