Hostname: page-component-76fb5796d-45l2p Total loading time: 0 Render date: 2024-04-27T02:29:16.929Z Has data issue: false hasContentIssue false

Thermal Expansion Behavior of Pure and Doped Cordierite by Time-of-Flight Neutron Diffraction

Published online by Cambridge University Press:  06 March 2019

J. Haas
Affiliation:
University of Denver, Denver, CO 80208
Paul Predecki
Affiliation:
University of Denver, Denver, CO 80208
J. Faber Jr.
Affiliation:
Argonne National Lab, Argonne, IL 60439
R. L. Hitterman
Affiliation:
Argonne National Lab, Argonne, IL 60439
Get access

Abstarct

In order to reveal the mechanism of the negative c-axis expansion in cordierite (4 MgO 4 Al2O3 10 SiO2), the thermal expansion of cordierite containing small amounts of Cs, Li, B, Ge, Sc and Ni-cations was investigated by time-of-flight neutron diffraction at temperatures between 22 and 750°C. The samples were prepared by melting the constituent oxides followed by quenching and devitrification to obtain the hexagonal form (Indialite). Using the neutron powder diffraction data, the atom positions in the space group P6/mcc were refined by Rietveld least squares analyses.

The expansion behavior of the cordierite structure could be explained in terms of the various kinds of constraints and the interatomic bond strengths of the structure. It was found that cordierite doped with Cs-cations shows the largest volume expansion, followed by the Li-doped sample. So-doped cordierite has the lowest volume expansion. All cordierite samples show positive expansion along the a-axis and negative expansion along the c-axis, except the Cs-doped sample which has positive expansion in both directions.

Type
VII. Synchrotron and Neutron Diffraction
Copyright
Copyright © International Centre for Diffraction Data 1986

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

*

Work supported by Division of Basic Energy Sciences, DOE, Washington, D.C., on grant #DE-FG02-84ER45053. One of the authors (JF) also acknowledges support of the U.S. DOE, BES-Materials Sciences, under contract W-31-109-Eng-38.

References

1. Von Dreele, H.B., Jorgensen, J.D. and Windsor, C.G., “Rietveld Befinement with Spallation Neutron Powder Diffraction Data”, J.Appl. Crystallogr., 15, 581-589 (1982).Google Scholar
2. Predecki, F.K., Haas, J., Faber, J. Jr., and Hitterman, R.L., “Lattice Thermal Expansion Effects in Pure and Doped Cordierite by Time-of- Flight Neutron Diffraction”, advances in X-ray Analysis, Vol. 29, p. 173184 (1986).Google Scholar
3. Robinson, K., Gibbs, G.V. and Bibbe, P.H., “Quadratic Elongation: A Quantitative Measure of Distortion in Coordination Polyhedra,“ Science 172: 567 (1971).Google Scholar
4. Haas, J., “Mechanism of Lattice Thermal Expansion in Pure and Doped Cordierite”, M. S. Thesis, Physics Dept., University of Denver, Denver, CO. (1986)Google Scholar