Phase transition and piezoelectric properties of (Pb, La) (Zr, Ti)O3 ceramics prepared from spray-dried powders

PLZT ceramic with compositions having molecular formulas (Pb,1-3x/2)La□x/2)(ZryTi1-3)O3 with O ltm I ltm 0.1 and 0.5 ltm y ltm 0.6 were prepared by cold compaction and sintering of chemically prepared powders. These powders were obtained by spray dried nitrates. Ferroelectric tetragonal, ferroelectric rhombohedral and paraelectric cubic phases of the compositions were identified and morphotropic phase boundary having <1 at.% transition region between the phases has been located by correlating the data on crystal structure, polarization characteristics and piezoelectric properties. Values of Pr,S1, ε, d33 and Kp have been found to be maximum for compositions lying at the morphotropic phase boundary. It has been observed that decrease in tetragonal and rhombohedral distortion of the unit cell causes enhancement in the ordering of ferroelectric domains and consequently provides improvement in piezoelectric properties.

Keywords:

• PLZT
• phase transition
• piezoelectric
• MPB
• spray drying