Preparation of ultrafine PZT powders by ultrasonic spray combustion synthesis (USCS)

Ultrafine PZT powders were synthesized by the ultrasonic spray combustion method from Pb(NO3)2, ZrO(NO3)2·xH2O, TiO(NO3)2, and CH6N4O precursors. The molar ratio of oxidizer and fuel was 1:1 for the maximum exothermic reaction. The DTA/TGA curves of the precursor mixture showed exothermic peaks for combustion. The external heating temperature for ultrasonic spray combustion synthesis was 800 °C. The ultrasonically generated droplets are filtered using a metal screen filter and Reynolds number was kept at a value of 1200 to avoid coagulation of droplets in the system. XRD analysis showed that the as-received powders without calcination were PZT. The lattice parameters calculated by X-ray methods were a=b=3.997±0.001 Å, c=4.147±0.001 Å. SEM and TEM observations showed that the particles of the synthesized tetragonal PZT powders had a 100-200 nanometer size with uniform spherical shape.