On the development of high density barium metazirconate (BaZrO3) ceramics

A simple, economically viable and easily scaleable technique for the bulk synthesis of phase-pure barium metazirconate (BaZrO3) is described. An equimolar ball-milled mixture of barium and zirconyl nitrates yielded fine-grained sin.-le-phase BaZrO3 powder after a single-stage calcination at 800degreesC. The cubic perovskite structure was found to be stable up to 1700degreesC, the maximum sintering temperature employed in this work. Pure BaZrO3 compacts with bulk density greater than or equal to90% of theoretical were successfully obtained using a two-stage sintering profile. Benign/deleterious effects of three sintering aids (viz. Al2O3, MgO and Y2O3) in terms of densification, shrinkage and microstructural variation in BaZrO3 were also evaluated. (C) 2002 Elsevier Science B.V. All rights reserved.