Rapid synthesis of submicron crystalline barium zirconate BaZrO 3 by precipitation in aqueous basic solution below 100 °C

Abstract

Pure crystalline BaZrO 3 powders can be produced by precipitation in highly basic aqueous solution. The influence of several synthesis parameters is studied. At high OH − concentration ([NaOH] = 20 mol/l), it is possible to obtain the well-crystallized stoichiometric perovskite phase at relatively low temperature (∼80 °C), after a short reaction time (15 min) and without requiring any precaution to avoid the presence of CO 2. This synthesis method yields spherical particles, whose size can be controlled by changing the concentration of the Ba + Zr solution. No calcination treatment is necessary since the precipitate is crystalline. Suitable choice of the synthesis parameters ([NaOH] = 20 mol/l, [Ba + Zr] = 1 mol/l, reaction time = 15 min) yields a sub-micron precipitate with excellent densification behaviour. Corrosion tests in BaO–CuO melt show that ∼98% dense BaZrO 3 obtained by sintering at 1650 °C for 13 h could be used for crucibles in the synthesis of YBa 2Cu 3O 7 superconducting single crystals.