X-RAY STRUCTURES OF HETEROEPITAXIAL GROWTHS

1. 研究了生长在GaAs（111）衬底上的外延CaSrF2晶体的结构及其界面结构。研究结果发表在《表面科学》杂志上。用x射线驻波技术研究了非薄EuBaCuo和GdBaCuO外延晶体在SrTiO3（001）表面的生长界面结构。实验数据表明，EuBaCuO和GdBaCuO都不能在SrTiO3的TiO2表面形成CuO层和CuO2层，同样，BaO层和稀土层也不能在SrO表面形成第一层。研究结果发表在《物理评论》杂志上。首次在超高真空条件下对as沉积Si（111）表面进行了掠角x射线站立实验。砷原子在三倍位置形成一个块状表面取代了顶层的硅原子。结果表明，砷原子占据了高对称位，无序性很小。这项研究发表在《物理评论》上。利用掠角x射线驻波技术在Si(100): As表面进行了初步实验。用掠角x射线反射率测量方法评价了机械化学抛光硅表面的微粗糙度。已经证明，该技术可以定量地确定2-5 A rms的粗糙度，而不会损坏样品。在j.j.j.p ap . phys.com上发表了一篇论文。

1. The structure of epitaxial CaSrF2 crystals grown on GaAs(111) substrates, as well as of their interfaces, have been fully characterized. The results have been published in Surface Science.2. The structure of growth interface of untrathin EuBaCuo and GdBaCuO epitaxial crystals on SrTiO3(001) surface have been investigated using the X-ray standing-wave technique. The experimental data show that for both EuBaCuO and GdBaCuO neither the CuO layr nor CuO2 layr can be the first grown layr on the TiO2 surface of SrTiO3 Similary, neither the BaO layr nor the rare-earth layr can be the first layr on the SrO surface. The results have been published in Physical Review.3. Grazing-angle X-ray standing experiments were performed for the first time on Asdeposited Si(111) surface under ultrahigh vacuum conditions. It has been confirmed that arsenic atoms form a bulklike surface replacing the top-layr Si atoms at the threefold positions. Evidences indicating that the As atoms occupy the high-symmetry sites with little disorder was obtained. The research has been published in Physical Review.4. Preliminary experiments were executed on Si(100) : As surface using the grazing-angle X-ray standing-wave technique.5. Microroughness of mechanochemically polished silicon surfaces has been evaluated by grazing-angle X-ray reflectivity measurements. It has been demonstrated that the technique can quantitatively determine roughnesses of 2-5 A rms without damaging the sample. An original paper was printed in J.Jpn.Appl.Phys.out of the work.