Specific features of preparation of dense ceramic based on barium zirconate

In the present work the BaZr$_{0.8}$Y$_{0.2}$O$_{3-\delta}$ samples were synthesized by traditional ceramic (solid-state method), citrate-nitrate methods as well as co-precipitation of hydroxides. Among them, the citrate-nitrate combustion method was found to be the optimal one because the obtained powder calcined at 1150$^\circ$C is single-phase and characterized by high dispersion. It is shown that the transition from solid-state method to wet chemical ones promotes the decrease of the powder particle size from $\sim$680 nm to 75 nm, respectively. However, at the same time the relative densities of the samples sintered at 1450$^\circ$C do not exceed the 67%. The dense ceramic (90.2%) was obtained by combination of the citrate-nitrate method and the addition of 1 wt% Co$_3$O$_4$ as a sintering aid to the precursors.