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Structure Refinement of Mullite by the Rietveld Method and a New Method for Estimation of Chemical Composition
Author(s) -
Ban Takayuki,
Okada Kiyoshi
Publication year - 1992
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1992.tb05473.x
Subject(s) - mullite , chemical composition , rietveld refinement , orthorhombic crystal system , materials science , mineralogy , chemistry , crystallography , crystal structure , ceramic , metallurgy , organic chemistry
The structure of mullite was refined by the Rietveld method, and a new method for the estimation of chemical composition of mullite was proposed. Mullites were synthesized by firing the starting materials prepared by sol–gel and spray pyrolysis methods at various temperatures. Linear correlations were recongnized between the chemical composition of mullite analyzed with the Rietveld method and the lengths of a and b axes, but a small anomaly was found in the variation of the c axis. It was found to be caused by a difference in the c axis of pseudotetragonal mullite and that of orthorhombic mullite. A good correlation was found between the chemical composition of mullite and the intensity ratio of ( I 220 / I 111 ). This is a much more convenient method for estimating the chemical composition of mullite than Cameron's method, which uses a lattice constant.