Temperature dependence of electromechanical properties of PLZT x/57/43 ceramics

摘要

The compositions of lead lanthanum zirconate titanate PLZT [Pb(Zr_(0.57)Ti_(0.43))O_3 + x at% of La, where x = 3, 5, 6, 10 and 12] have been synthesized using mixed oxide route. The temperature dependent electromechanical parameters have been determined using vector impedance spectroscopy (VIS). The charge constant d_(31) and elastic compliance s_(11)~E show a peak in all the samples at a temperature T_(mt) much below the ferroelectric - paraelectric transition temperature, whereas the series resonance frequency f_s shows a dip at these temperatures. The Poisson's ratio σ~E increases with temperature T showing a broad peak at a temperature higher than T_(mt). The voltage constant g_(31) decreases and the planar coupling coefficient K_p remains constant up to half of the T_(mt) and then falls sharply with T. Half of the T_(mt) can, therefore, be used for specifying the working temperature limit of the piezoceramics for the device applications.