Nano-sized BaSnO3 Powder via a Precursor Route. Comparative Study of Sintering Behaviour and Mechanism of Fine and Coarse-grained Powders.

Abstract.

J. Eur. Ceram. Soc. 29 (2009) 2317-2324. (DOI: 10.1016/j.jeurceramsoc.2009.01.026).

Preparation of a very fine BaSnO3 powder by calcination of a barium tin 1,2-ethanediolato complex precursor and its sintering behaviour are described herein. A rate controlled calcination process to 820 °C leads to a nm-sized BaSnO3 powder with a specific surface area of S = 15.1 m2/g (dav. = 55 nm). The powder has a slightly larger cell parameter of a = 412.22(7) pm compared to the single crystal value, which decreases with increasing calcination temperature and reaches the reference value above 1000 °C. The sintering behaviour is compared between fine- and coarse-grained BaSnO3 powders. Corresponding powder compacts of the nano-sized BaSnO3 achieve a relative density of 90 % after sintering at 1600 °C for 1 h and at 1500 °C and a soaking time of 30 h, whereas coarse-grained powder compacts reach only 80 % of the relative density at 1650 °C (10 h). Furthermore, the shrinkage mechanisms of fine and coarsegrained powder compacts have been investigated and are discussed.