Analyzes of the structure, crystallite size and internal strain of a small crystal by a x-ray powder diffraction method

本研究旨在通过对甘多菲相机获得的x射线粉末衍射数据应用剖面拟合技术，确定小于100mum的极小晶体的精确晶格参数、晶体尺寸和内部应变。现将本研究所得的结果简要总结如下：1。利用甘多菲相机对x射线衍射数据进行拟合，可以在小于0.01‰（2‰）.2的误差范围内确定每条衍射线的2‰位置。对于在衍射图的高角范围内给出清晰衍射线的晶体，可以用外推法精确地确定极小晶体的晶格参数。对于在衍射图高角度范围内没有清晰衍射图样的晶体，采用内标法估计了衍射线位置的系统误差。用丙烯酸酯作为分散剂，用标准材料包覆一个小于100微米的小晶体。在对系统误差进行校正后，利用最小二乘技术可以精确地确定极小晶体的晶格参数。参考标准材料的积分宽度对机械线展宽进行修正后，可以用Williamson-Hall法估计极小晶体的晶体尺寸和内部应变。

This study aimed to determine the precise lattice parameters, crystallite size and internal strain of a very small crystal less than 100mum by applying a profile fitting technique to the x-ray powder diffraction data obtained with a Gandolfi camera. The brief summary of the results obtained in this study is as follows.1. By an application of a profile-fitting technique to the x-ray diffraction data obtained with a Gandolfi camera, the 2 rheta position of each diffraction line can be determined within an error of less than 0.01ﾟ(2rheta).2. In the case of the crystal which gives clear diffraction lines in the high angle range of a diffraction diagram, the lattice parameters of a very small crystal can be determined precisely by an extrapolation method.3. For the crystal which does not show a clear diffraction pattern in the high angle range of a diffraction diagram, an internal standard method was applied to estimate the systematic errors included in the diffraction line positions.A very small sized crystal less than 100 mum was coated with a standard material by using a syanoacrylate as the dispersing agent. After the correction of systematic errors, the lattice parameters of a very small crystal can be determined precisely by using a least-square technique.4. After the correction of the mechanical line broadening by referring the integral breadth of a standard material, the crystallite size and internal strain of a very small crystal can be estimated by the Williamson-Hall method.