ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Amorphous oxide combustion products with compositions corresponding to Y4Al2O9, YAlO3, and Y3Al5O12 were synthesized by the glycine-nitrate process and heat-treated to induce crystallization. The crystalline structure of the resulting powders was determined by powder X-ray diffraction techniques. The phase stabilities of the crystalline phases were investigated as functions of the glycine-to-nitrate ratio, the yttrium-to-aluminium ratio, and the heat-treatment conditions. Heat treatment for short durations resulted in incompletely crystalline powders that consisted of a mixture of Y4Al2O9, YAlO3, and Y3Al5O12 phases, regardless of the chemical composition of the amorphous combustion product. However, heat treatment for longer durations or higher temperature generated both pure-phase, monoclinic Y4Al2O9 and Y3Al5O12 with the garnet structure. Prolonged heat treatment at high temperature failed to generate pure-phase orthorhombic YAlO3. Subsequent analysis revealed a sluggish, complex crystallization process involving the formation and decomposition of several phases.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00351307
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