iC多型体X射线定量分析的Rietveld方法

鉴于SIC多型体的主要衍射线完全重叠，用常规X射线粉末衍射方法确定SiC陶瓷材料中多型体含量的分布是非常困难的．提出以X射线粉末衍射全谱拟合的Rietveld方法进行SiC多型体定量分析，阐述了原理及方法．对含3C，4H，6H和15R4种多型体衍射数据的定量分析结果表明：Rietveld方法可对SiC材料中常见多型体的定量分析给出准确的结果．还给出了各自的标准偏差，并估计了该方法对各多型体能给出精确结果的最低含量

X-RAY POWDER DIFFRACTION RIETVELD METHOD IN-QUANTITATIVE DETERMINATION OF SiC POLYTYPES

It is very difficult to obtain SiC polytypes distribution by normal X-ray powder diffraction quantitative phase analysis methods. The whole pattern fitting Rietveld method is introduced to address this problem. The principle and advantages of Rietveld method in determining SiC polytypes distribution are described. The final results show that the distribution of the most common four SiC polytypes, 6H, 4H, 3C and 15R, can be given accurately. The detection limits of each polytypes are also estimated based on their standard deviations