Effect of Calcination Temperature on Phase Transformation and Microstructure of Al₂O₃/GdAlO₃ Compound Powder Prepared by Co-Precipitation Method

Abstract:

A Coprecipitation Method Was Applied to Synthesize Al₂O₃/GdAlO₃ Compound Powder, Using Ammonia as the Precipitator. Gadolinium Oxide and Aluminium Nitrate Were Used as the Raw Materials with the Eutectic Ratio( 77 mol% Al ³⁺ – 23 mol% Gd ³⁺ ). the Precursor Was Calcined at Different Temperatures from 1200 to 1600 °C. the Phase Identifications at Different Temperatures Were Characterized by X-ray Diffractometry (XRD). the Growth Morphology of Particles Were Investigated Using Field Emission Electro Microscopy (FE-SEM). the Results Reveal that GdAlO₃ Crystallized Earlier than α-Al₂O₃. the Diffraction Peaks of α-Al₂O₃ Phase Were Observed after Calcination at 1300°C for 1 H. Metastable Phase Gd₃Al₅O₁₂ Underwent Complete Decomposition at 1600°C for 1 H. Gadolinium Aluminate and α-Al₂O₃ Showed Different Growth Mechanism during the Calcination Process. the Average Grain Size of the Calcined Powder Increased from ~40 to ~900 Nm as the Calcination Temperature Increased from 1200 to 1600 °C.

• Periodical: Key Engineering Materials (Volumes 512-515)
• Pages: 535-538
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.512-515.535
• Online since: June 2012
• Authors: Shuai Sun, Qiang Xu
• Keywords: Al₂O₃, GdAlO₃, Morpholoy, Phase Transformation

References

[1] W.Q. Li and L. Gao, Processing, microstructure and mechanical properties of 25 vol% YAG-Al2O3 nanocomposites, J. Nanostruct. Mater. 11(1999)1073-1080.

DOI: 10.1016/s0965-9773(99)00396-7

[2] C. Oelgardt, J. Anderson, J.G. Heinrich, et al, Sintering, microstructure and mechanical properties of Al2O3–Y2O3–ZrO2 (AYZ) eutectic composition ceramic microcomposites, J. Eur Ceram Soc. 30 (2010) 649-656.

DOI: 10.1016/j.jeurceramsoc.2009.09.011

[3] S. Chaudhury, S.C. Parida, K.T. Pillai, et al, High-temperature X-ray diffraction and specific heat studies on GdAlO3, Gd3Al5O12 and Gd4Al2O9, J. Solid State Chem. 180 (2007)2393-2399.

DOI: 10.1016/j.jssc.2007.06.003

[4] G.S.R. Raju, J.Y. Park, H.C. Jung, et al, Luminescence properties of Dy3+:GdAlO3 nanopowder phosphors, J. Curr Appl Phys. 9 (2009)e92-e95.

DOI: 10.1016/j.cap.2008.12.037

[5] Y. Kanke and A. Navrotsky, A Calorimetric Study of the Lanthanide Aluminum Oxides and the Lanthanide Gallium Oxides:Stability of the Perovskites and the Garnets, J. Solid State Chem. 141 (1998)424-436.

DOI: 10.1006/jssc.1998.7969

[6] U. Kolitsch, H.J. Seifert and F. Aldinger, Phase relationships in the system Gd2O3-Al2O3-SiO2 , J. Alloys Compd. 257 (1997)104-114.

DOI: 10.1016/s0925-8388(96)03121-0

[7] Y. Harada, K. Ayabe, N. Uekawa, et al, Formation of GdAlO3–Al2O3 composite having fine pseudo- eutectic microstructure, J. Eur Ceram Soc. 28 (2008)2941-2946.

DOI: 10.1016/j.jeurceramsoc.2008.04.025