Barium strontium zirconate titanate ((Ba 1−x Sr x )(Zr x Ti 1−x )O 3 ; BSZT, x = 0.25 and 0.75) ceramics with a highly crystalline structure were successfully synthesized using the combustion technique, in which urea performed an important role. The effect of calcination (1000-1300 • C) and sintering temperatures (1300-1550 • C) on the phase formation and microstructure of BSZT ceramics were investigated. The pure perovskite phase of BSZT (x = 0.25 and 0.75) powders with a uniform cubic morphology were detected at the calcination temperature of 1300 • C. At the same calcination and sintering temperature, the lattice parameter a of BSZT powder and ceramics with x = 0.75 is higher than x = 0.25. The microstructure of BSZT powders exhibited an almost-spherical morphology and had a porous agglomerated form. The average particle size and the average grain size of all ceramics increased with the increase of calcination and sintering temperatures, but decreased when the content of x increased. The maximum densities of x = 0.25 and 0.75 ceramics were around 5.85 and 5.62 g cm −3 obtained from the samples sintered at 1500 and 1450 • C, respectively.

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The effect of calcination (1000-1400 oC) and sintering temperatures (1400-1600 oC) on the phase formation and microstructure of barium strontium zirconate titanate [(Ba0.25Sr0.75)(Zr0.75Ti0.25)O3; BSZT] ceramics were investigated. BSZT powders were prepared by the solid-state reaction method. Higher calcination temperatures increased the percentage of the perovskite phase, but decreased the lattice parameter a of BSZT powders. The pure perovskite phase of BSZT powders was detected above the calcination temperature of 1350 oC. The microstructure of BSZT powders exhibited an almost-spherical morphology and had a porous agglomerated form. The average particle size and the average grain size of the ceramics were increased with the increase of calcination and sintering temperatures. The highest density of the samples was 5.42 g/cm3 which was obtained from ceramic sintered at 1550 oC for 2 h.

The effect of calcination temperatures (1000-1400 oC) on the phase formation and microstructure of barium strontium zirconate titanate [(Ba0.25Sr0.75)(Zr0.75Ti0.25)O3 ; BSZT] powders were investigated. BSZT powders were prepared and compared by the solid state reaction method and the combustion technique. The higher calcination temperatures increased the percentage of the perovskite phase, but decreased the lattice parameter a. The same crystallographic pure perovskite phase of BSZT powders, which were prepared via the combustion technique were detected above 1300 oC ; which was lower than the calcinations temperature of mixed oxide method by 50 oC. The TGA-DTA results corresponded to XRD investigation. The microstructure of BSZT powders, which were prepared using both techniques, exhibited an almost-spherical morphology and had a porous agglomerated form. The average particle sizes of BSZT powders prepared via the combustion technique (0.13-0.30 µm) and the solid state reaction method (0.18-0.38 µm) were increased with the increase of calcinations temperatures