Development and application of a rapid analysis method of a nanostructure by direct observation of a reciprocal-lattice space using synchrotron diffraction

我们开发了一种快速表征晶体纳米结构的无损分析方法，并将其应用于一维和二维纳米尺度材料的结构分析。该方法被命名为“一目了然”x射线方法，需要单色高能x射线在掠射入射和x射线二维探测器。该方法背后的基本思想是，这种一维结构的布拉格条件是片状的，并且是松散的。该方法允许对从ID和2D散射的x射线强度进行直接的往复式晶格空间映射，并具有超高灵敏度的特点。(1)利用该方法，观察了超薄NiO线发出的片状衍射。纳米线-纳米线的平均距离为46 nm，纳米线上的晶体学畴尺寸约为15 nm。(2)我们利用x射线衍射证明，我们已经在Si（001）表面制备了一维Bi纳米线（原子线），并将它们埋在晶体硅中，同时保留了它们的一维特性和结构的重要方面。特别是，在埋藏之后，纳米线沿其长度保留与其表面结构相关的二乘周期性。我们使用密度泛函理论计算来模拟这些埋藏纳米线的结构，其最小长度可以从x射线测量的相干长度估计为100纳米。(3)用该方法研究了在TiO_2晶体上生长的50 nm和3 nm厚的Bi_4Ti_3O_<12>铁电薄膜。测定薄膜为单斜晶。

We developed a nondestructive analysis method for quickly characterizing a crystalline nanostructure and applied it to structural analysis of 1D and 2D nanometer scale materials. The method, which was named "obvious-at-a-glance" x-ray method, required monochromatic high-energy x-rays in grazing incidence and an x-ray 2D detector. The basic idea behind the method is that Bragg conditions of such 1D structures are sheet shapes and get loose. The method has allowed a direct reciprocal-lattice space mapping of the x-ray intensities scattered from the ID and 2D and bears characteristics of super-high-sensitivity.(1)Using this method, the sheet-shape diffraction emanating from ultrathin NiO wires was observed. The average nanowire-nanowire distance of 46 nm and a crystallographic domain size of approximately 15 nm across the nanowire were evaluated.(2)We demonstrate, using x-ray diffraction, that we have taken one-dimensional Bi nanolines (atomic wires) fabricated on a Si(001) surface, and buried them in crystalline silicon while retaining both their one-dimensional characters and important aspects of their structure. In particular, after burial, the nanolines retain the two-by periodicity associated with their surface structure along their length. We have used density functional theory calculations to model a structure for these buried nanolines, whose minimum length can be estimated to be 100 nm from the coherence length of the x-ray measurements.(3)50-nm- and 3-nm-thick Bi_4Ti_3O_<12> ferroelectric films grown on TiO_2 crystals were investigated using the method. It was determined that the thin films were monoclinic crystals.