Sintering of a Fine-Grained BaCeO3 Powder Obtained from a Co-Precipitation Method
Journal of Material Science (2010) 45:6521–6527
21 Pages Posted: 23 Jan 2018
Date Written: July 7, 2010
Abstract
The formation of BaCeO3 by a co-precipitation method is described herein. The coprecipitation route leads to an orange (BaCe)-precursor powder. To improve the sintering behaviour, a small amount of Ge4 was incorporated, leading to a (BaCe0.95/Ge0.05)-precursor. Both precursor powders results in fine-grained preceramic powders (1A, 2A) after calcination. The shrinkage and sintering behaviour of resulting powder compacts were studied in comparison to a coarse-grained mixed-oxide BaCeO3 powder. Compacts of 2A reach a relative density of 90 % after sintering at 1350 °C with grain-sizes between 0.9−3.2 μm. On the other hand ceramics of 1A and 3 have, after sintering at 1500 °C (10 h), relative densities of 85 % and 76 %, respectively. Ceramic bodies of 1A consisted of phase-pure orthorhombic BaCeO3, whereas bodies of 2A show reflections of BaCeO3 and a Ba2GeO4 phase. DTA investigations of samples 1A and 2A reveal three phase transitions at 255 °C (1A) and 256 °C (2A) as well as 383 °C (1A) and 380 °C (2A). A very weak one can be obtained in the range 880−910 °C.
Keywords: BaCeO3, sintering, phase transition
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