Micro-structural, dielectric, ferroelectric and piezoelectric properties of mechanically processed (Pb_(1-x)La_x)(Zr_(0.60)Ti_(0.40))O_3 ceramics

摘要

In this work, (Pb1-xLax)(Zr0.60Ti0.40)O-3 (PLZT x/60/40, x = at.%) ceramics were prepared by using high energy mechanical ball milling followed by cold isostatic pressing (CIP), investigated for their micro-structural, dielectirc, ferroelectric and piezoelectric properties. Mechanical activation results in the highly reactive nature of the nano size milled PLZT powders, which enables the partial perovskite phase formation, confirmed by room temperature XRD patterns. CIP leads to a higher density with a closely packed dense microstructure of sintered PLZT ceramics shown in SEM images. The grain size of PLZT x/60/40 ceramics was found to be decreasing with increasing La3+ content. The highest relative density of similar to 97% was found to be for PLZT 8/60/40 ceramics with grain size of similar to 1.35 A mu m. The PLZT 8/60/40 system also shows the highest dielectric constant of similar to 1976, remnant polarization of 29.1 A mu C/cm(2), piezoelectric coefficients (d(33) 570 pC/N, g(33) 28.03 x 10(-3) Vm/N) and electromechanical coupling factors (k(p) = k(33) = 64.1% and k(31) = 54%). The elastic compliances for the PLZT x/60/40 ceramics were also obtained.