Effect of Processing on the Dielectric and Piezoelectric Properties of Pb(Mg_1/3,Nb_2/3)O₃-32.5PbTiO₃ Ceramics Prepared without Excess PbO

Abstract

The morphotropic phase boundary (MPB) composition of (1−x)Pb(Mg_1/3,Nb_2/3)O₃-xPbTiO₃ (x = 0.32) was synthesized by the columbite precursor method without the use of any excess PbO for densification. Ceramics were prepared using two atmospheres viz. sintering in air and oxygen, respectively to study the effect of these different processing conditions on the sintering process. High-density ceramics were formed when samples were sintered in an oxygen environment. The high density and absence of excess PbO, resulted in excellent dielectric, ferroelectric and piezoelectric properties. Dielectric constants on the order of ∼41,500 were recorded at the T_c. A maximum strain level of ∼0.17% at ∼30 kV/cm, associated with a piezoelectric constant (d₃₃) of 785 pC/N was obtained on the samples having the highest density.

Keywords:

• Lead based ferroelectrics
• piezoelectric coefficients
• sintering
• permittivity

Acknowledgments

The author would like to thank Prof. G. L. Messing and Prof. Susan Trolier-McKinstry of the Materials Research Laboraroty, Pennsylvania State University, for the many useful discussions and supporting this project.

This work was carried out at the Materials Research Institute, Pennsylvania State University, University Park, PA 16802, USA.