Synthesis and Sintering of Nano-sized BaSnO3 Powders Containing BaGeO3

19 PAGES (3480 WORDS) Chemistry Article/Essay

Abstract.

J. Mater. Sci. 45 (2010) 3784–3790. (DOI: 10.1007/s10853-010-4432-5).

The formation of solid solutions of the type [Ba(HOC2H4OH)4][Sn1−xGex(OC2H4O)3] as BaSn1-x/GexO3 precursor and the phase evolution during its thermal decomposition are described in this paper. The 1,2-ethanediolato complexes can be decomposed to nano-sized BaSn1−x/GexO3 preceramic powders. Samples with x = 0.05 consist of only a Ba(Sn,Ge)O3 phase, whereas powders with x = 0.15 and 0.25 show diffraction patterns of both the Ba(Sn,Ge)O3 and BaGeO3 phase. The sintering behaviour was investigated on powders with a BaGeO3 content of 5 and 15 mol%. These powders show a specific surface area of 15.4−15.9 m2/g and were obtained from calcination above 800 °C. The addition of BaGeO3 reduced the sintering temperature of the ceramics drastically. BaSn0.95Ge0.05O3 ceramics with a relative density of at least 90 % can be obtained by sintering at 1150 °C for 1 h. The ceramic bodies reveal a fine microstructure with cubical-shaped grains between 0.25−0.6 μm. For dense ceramics the sintering temperature could be reduced down to 1090 °C, when the soaking time was extended up to 10 h.