Effect of MgO on piezoelectric, dielectric and ferroelectric properties of (Ba_(1-x) Mg_x) (Ti_(0.98) Zr_(0.02)) O_3 lead-free piezoceramics

摘要

Effect of MgO on ferroelectric, dielectric, piezoelectric properties of (Ba_(1-x) Mg_x) (Ti_(0.98) Zr_(0.02)) O_3, (x = 0.00, 0.01, 0.015, 0.02 and 0.03 mol) lead free piezoceramics was studied. The powders were prepared by conventional solid state reaction method, calcined at 1000 ℃ for 4 h. XRD patterns of the calcined powders show phase pure perovskite structure. The calcined powders were de-agglomerated, pressed into pellets and sintered at 1150 ℃ for 3 h. Scanning electron microscopy studies of thermally etched sintered pellets show sub-micron sized grains for undoped BZT and 3-5 μm sized grains for 0.01 mol MgO doped BZT. Energy dispersive X-ray analysis of MgO doped BZT sample confirms the presence of dopants very close to their stoichiometric compositions. The piezoelectric charge constant (d_(33) = 164 pC/N), dielectric constant (K = 2348) and remnant polarization (P_r = 3.3 μC/cm~2) were maximum for BZT samples containing 0.01 mol of MgO.