Synthesis and electrical properties of CaO doped BZT lead free piezo ceramics

Effect of CaO on ferroelectric, dielectric, piezoelectric properties of Barium Zirconate Titanate (BZT) lead free piezo ceramics was studied. The powders were prepared by mixed-oxide route, calcined at 1000°C for 4 h. XRD patterns of the calcined powders show phase pure perovskite structure. The calcined powders were de-agglomerated, granulated, pressed into pellets and sintered at 1150°C for 3 h. Scanning Electron Microscopy (SEM) studies of thermally etched sintered pellets show sub-micron sized grains for undoped BZT which increases up to 5–8 μm sized for 0.015 mol CaO doped BZT. Energy Dispersive X-ray analysis (EDS) of CaO doped BZT sample confirms the presence of dopants very close to their stoichiometric compositions. The piezoelectric charge constant (d33 = 248 pC/N), dielectric constant (K = 2521) and remnant polarization (Pr = 4.22 μC/cm2) were maximum for BZT samples containing 0.015 mole of CaO