RIETVELD ANALYSIS AND MEM-BASED WHOLE-PATTERN FITTING UNDER PARTIAL PROFILE RELAXATION
RIETVELD ANALYSIS AND MEM-BASED WHOLE-PATTERN FITTING UNDER PARTIAL PROFILE RELAXATION
复制标题
部分轮廓松弛下的RIETVELD分析和基于MEM的全模式拟合
DOI：
--
复制
发表时间：
2000
期刊：
影响因子：
--
通讯作者：
F. Izumi
中科院分区：
文献类型：
--
作者：
F. Izumi
Rietveld方法[1]已被广泛用作细化各种金属和无机化合物结构参数的领先技术。粉末衍射图中高Q区（Q = 1.2Q = 2π/d; Q：散射矢量，d：晶格面间距）的反射严重重叠，限制了从粉末衍射图中提取的结构信息的质量和数量。然而，近年来同步加速器X射线粉末衍射[2]和飞行时间（TOF）中子粉末衍射的进步显著提高了分辨率，使我们能够确定非常复杂的结构，这些结构以前很难用粉末数据进行分析。自著名的《里特维尔德方法》一书中介绍里特维尔德分析程序RIETAN [3]以来，已经过去了五年。“RIETAN有两个版本用于角色散衍射[3，4]和TOF中子衍射[5]。它已被广泛使用，特别是在日本，有助于大量的结构研究。例如，第一高T.用RIETAN解决了萤石和碳酸盐块的超导体的TOF中子衍射[6]。本文回顾了RIETAN的最新进展，重点是我们的原始技术：部分轮廓松弛[7-9]和基于最大熵方法（MEM）的整体模式拟合[8，10]。
The Rietveld method [1] has been extensively used as a leading technique for refining structure parameters of a variety of metal and inorganic compounds. The severe overlap of reflections in the highQ region (Q =Q = 2π/d; Q: scattering vector, d: lattice-plane spacing) in powder diffraction patterns limits the quality and amount of structural information extractable from them in comparison with singlecrystal data. However, advances in synchrotron X-ray powder diffraction [2] and time-of-flight (TOF) neutron powder diffraction in recent years have enhanced the resolution, ∆d/d, pronouncedly, enabling us to determine very complex structures whose analyses were formerly difficult with powder data. Five years have passed since a Rietveldanalysis program RIETAN [3] was introduced in the wellknown book entitled "The Rietveld Method." RIETAN has two versions for angle-dispersive diffraction [3, 4] and TOF neutron diffraction [5]. It has been widely utilized, particularly in Japan, contributing to a large number of structural studies. For example, the structures of the first High-T. superconductors with fluorite and carbonate blocks were solved with RIETAN for TOF neutron diffraction [6]. This article reviews recent advances in RIETAN with a focus on our original technology: partial profile relaxation [7-9] and whole-pattern fitting based on a maximum-entropy method (MEM) [8, 10].