Dielectric and Ferroelectric Studies on Sol-Gel Derived Calcium Modified Lead Zirconate Titanate Ceramics

摘要

Bulk samples of Pb_((1-x))Ca_xZr_(0.52)Ti_(0.48)O_3=0,0.02,0.04,0.06,0.08,0.1) have been syn-thesized by sol-gel process using lead acetate trihydrate, calcium acetate hydrate, zirconium propoxide and titanium propoxide as the starting materials. The dependence of ferroelectric phase transition temperature T_c as a function of calcium substitution has been investigated. A linear decrease of T_cis observed with increasing calcium concentration. The variation of room temperature dielectric constant and that of maximum value of dielectric constant corresponding to the phase transition temperature are explained by the microstructural studies. XRD patterns of the samples show that all the compositions sintered at 1200℃ are having single phase with perovskite structure. P-E hysteresis loop measurements showed that calcium modified PZT ceramics have higher Pr values than that of pure PZT composition prepared by sol-gel method. The composition with 4 mol% calcium has the highest value of P_r, 25.2 μC/cm~2and lowest E_c,9.6 kV/cm.