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High-temperature X-ray powder diffraction analysis of selected ceramic mixtures

Published online by Cambridge University Press:  10 January 2013

Sampath S. Iyengar
Sampath S. Iyengar
Affiliation:
Analytical Materials Laboratory, P.O. Box 1141, Lompoc, California 93438
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Abstract

The utility of ultra-high-temperature (2100 °C) X-ray powder diffraction technique for investigating the high-temperature phase relationships of two pseudobinary mixtures, Al2O3/Y2O3 and AlN/SiO2, is described. The in situ analysis to 1600 °C was carried out using a platinum holder and a Pt/Rh thermocouple; whereas analysis beyond 1600 °C was performed with a tungsten holder, extremely pure, oxygen-free inert gas environment, and an opticalpyrometer to monitor temperatures up to 2100 °C. The solid-state interaction between Al2O3 and Y2O3 commenced with the formation of Al2Y4O9 (YAM), a yttria rich compound, at 1300 °C followed by AlYO3 (YAP) and Al5Y3O12 (YAG) at 1400 °C. Further heating to 1500 °C and above resulted in the increased concentration of YAG at the expense of the other two phases, followed by melting of the entire sample at 2050 °C. The only phase formed during cooling (from the molten state) was YAG. AlN and SiO2 did not react with each other, in an inert atmosphere, and they remained as separate, discrete phases even at 1600 °C. In the presence of oxygen, they reacted to form mullite and cristobalite, or SIALON depending on the partial pressure of oxygen.

Type
Research Article
Information
Powder Diffraction , Volume 9 , Issue 1 , March 1994 , pp. 38 - 43
Copyright
Copyright © Cambridge University Press 1994

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References

Cockayne, B., and Lent, B. (1979). “A Complexity in the Solidification Behavior of Molten Y3Al5O12,” J. Crystal Growth 46, 371–378.CrossRefGoogle Scholar
Green, R. W (1991). “High Temperature XRD Analysis of Polymers,” Adv. X-ray Anal. 34, 459–464.Google Scholar
Himmelfarb, P. B., Wawner, F. E. Jr., Bieser, A. Jr., and Vines, S. N. (1983). “Oxidation States of Copper during Reduction of Copper Oxide in Methanol Catalysts,” J. Catalysis 83, 469–471.CrossRefGoogle Scholar
Iyengar, S. S. et al. , (1985). “High Temperature XRD Studies of Selected Carbonate Minerals,” Adv. X-ray Anal. 28, 331–338.Google Scholar
Iyengar, S. S. (1992). “Experimental Considerations and Limitations in the Application of Ultra-High Temperature (2100) X-ray Diffraction,” Adv. X-ray Anal. 35, 425–429Google Scholar
Loza, R. B., and Butler, R. J. (1986). “High Temperature X-ray Diffraction Studies on Nitrile Coatings,” Material Science Eng. 55, 557.Google Scholar
Rigaku Instruction Manual (The Rigaku Corporation, Danvers, MA).Google Scholar
Tissot, R. G., and Eatough, M. O. (1991). “Practical and Unusual Applications in X-ray Diffraction Using Position Sensitive Detectors,” Adv. X-ray Anal. 34, 349–356.Google Scholar