Rietveld方法中高角数据截断对结果的影响

应用科学学报 ›› 1997, Vol. 15 ›› Issue (2): 136-142.

Rietveld方法中高角数据截断对结果的影响

刘红超, 郭常霖

中国科学院上海硅酸盐研究所

收稿日期:1995-10-20 出版日期:1997-06-30 发布日期:1997-06-30
作者简介:刘红超:博士,中国科学院上海硅酸盐研究所,上海 200050

EFFECTS OF DIFFRACTION ANGLE TRUNCATION ON THE RESULTS OF RIETVELD ANALYSIS

LIU HONGCHAO, KUO CHANGLIN

Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050

Received:1995-10-20 Online:1997-06-30 Published:1997-06-30

摘要/Abstract

摘要： Rietveld方法是研究晶体结构和微结构的有效方法,但不同的数据处理将直接影响Riotveld方法所给出的结果.该文研究了数据处理中高角数据截取对Rietveld方法结果的影响不同的结构参数对高角数据截取有不同的灵敏度,一般的结构参数在常规衍射角范围就能取得较好的结果,但对轻原子体系和晶胞参数的准确确定,需要在计算中引入一定的高角衍射数据.在参数修正时,可信度因子的值随高角数据的增多而缓慢变化,且对背景参数的改变较为敏感。以至其值的大小不能准确反映晶体结构和微结构模型的有效性.

关键词: 可信度因子, 数据截断, Rietveld方法, 晶体结构

Abstract: Rietveld method is an efficient way to find out the crystal structure and micro-structure of solids. Data treatment strategy has great effect on the its results. In this paper, the effects of truncating angle on its results were sindied systematically. It was found that the site coordination of heavy atoms can be obtained at medium diffraction angle while it needs more high angle data in order to determine the cell parameters and site coordination of light atoms. With the increase of data at high diffraction angular range, the profile parameters almost keep constants; the changes of numerical criteria of fit(including D-wd) are etermined by background parameters.

Key words: numerical criteria of fit, Rietveld method, truncating angle, crystal structure

刘红超, 郭常霖. Rietveld方法中高角数据截断对结果的影响[J]. 应用科学学报, 1997, 15(2): 136-142.

LIU HONGCHAO, KUO CHANGLIN. EFFECTS OF DIFFRACTION ANGLE TRUNCATION ON THE RESULTS OF RIETVELD ANALYSIS[J]. Journal of Applied Sciences, 1997, 15(2): 136-142.