Effect of Variations in Stoichiometry on the Surface Structure of SrTiO3 (001)
Effect of Variations in Stoichiometry on the Surface Structure of SrTiO3 (001)
复制标题
化学计量变化对 SrTiO3 (001) 表面结构的影响
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
D. Bonnell
中科院分区：
文献类型：
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作者：
Yong Liang;D. Bonnell
用卢瑟福背散射和俄歇电子能谱对高温暴露于还原环境中的SrTiO{sub3}(001)表面的化学计量比变化进行了定量研究。除了预期的氧损失外，阳离子-阳离子比也有系统地变化。具体地说，在所有温度下，表面都变得缺乏钛和氧。扫描隧道显微镜测定的表面结构表明，该表面具有非化学计量比，其特征亚氧化物的周期结构为：sr{subn+1}Ti{subn}O{sub3n+1}。根据升华和分离的质量传输模型，讨论了化学和结构的变化。由于以前的表面研究关注的是溅射的影响或化学计量比表面的行为，这里给出的结果是首次系统地研究了(001)表面在退火时的成分变化。
Variations in stoichiometry of SrTiO{sub 3} (001) surfaces with high-temperature exposure to reducing environments were quantified with Rutherford backscattering and Auger electron spectroscopies. In addition to the expected oxygen loss, cation-cation ratios varied systematically. Specifically, the surface becomes Ti- and O-deficient at all temperatures. The associated surface structures determined by scanning tunneling microscopy showed that the surface accommodates nonstoichiometry by adopting periodic structures of characteristic suboxides with the formula Sr{sub n+1}Ti{sub n}O{sub 3n+1}. The chemical and structural variations are discussed in terms of mass transport models for sublimation and segregation. Since previous surface studies had been concerned with effects of sputtering or the behavior of stoichiometric surfaces, the results presented here represent the first systematic study of compositional variations upon annealing of the (001) surface.