Solution combustion synthesis of calcium zirconate, CaZrO3, powders

Single-phase CaZrO3 powder was prepared by heating at 300 °C an aqueous solution of Ca(NO3)2, ZrO(NO3)2 and β-C3H7NO2 (molar ratio=3:3:4). TG–DTA analysis indicated that an intense exothermic reaction occurred at 255 °C, which lead to the formation of a voluminous white powder. No additional annealing was required, as pure crystalline CaZrO3 resulted directly from the combustion reaction. Although no advanced milling was performed, the specific surface area of the powder was 21.5 m2/g. The average crystallite size of CaZrO3 was 23.9 nm. After sintering in air at 1400 °C for 2 h, the pellets – shaped by uniaxial pressing at 200 MPa – reached 95% of the theoretical density, had no open pores and were slightly translucent.