Study of Surface Structure by means of Correlated Thermal Diffuse Scattering.

本研究项目的目的是使用最近开发的技术，相关热漫散射（CTDS）的准确的表面结构调查。研究了这些方法的特点和不足之处，以提高性能。在此基础上，构建了新的二维衍射图样检测系统。该系统由一台冷激CCD摄像机、一个高动态范围视频图像采集卡和一台个人计算机组成。新的检测系统将数据采集时间加快了8倍以上，并且能够访问大量的衍射数据，这对于精确的结构调查至关重要。用CTDS研究了Si（001）2x1表面和Si（111）root3xroot3表面的表面结构，得到了清晰的表面结构，其结果与以前用其它方法研究的结果一致。与以往的比较表明，本CTDS的结构精度很高，约为0.1A。

The purpose of this research project is the accurate surface structure investigation using a recently developed technique, the correlated thermal diffuse scattering (CTDS). Characteristics and weak points of the methods have been investigated to improve the performance. Then the new two-dimensional detection system for diffraction patterns has been constructed. The system consists of a chilled CCD video camera, a high dynamic range video frame grabber and a personal computer. The new detection system speeds up the data acquisition time more than 8 times of those using the previous system, and enables to access a large volume of the diffraction data, which is crucial for the accurate structural investigation. Si (001) 2x1 surface and Si (111) root3 x root3 surface have been investigated by the CTDS using the new detection system The surface structures of both surfaces are clearly reconstructed by CTDS, and the results are consistent with those for previous studies by other methods. The comparison between the present and previous indicates the high structural accuracy, which is about 0.1A, of the present CTDS.