New antiferroelectric solid solution of Pb (Mg 1/2 W 1/2) O 3- Pb (Zn 1/2 W 1/2) O 3 as dielectric ceramics

Abstract

A new solid solution of (1-x)Pb(Mg1/2W1/2)O 3-xPb(Zn1/2W1/2)O3 has been prepared in the form of ceramics by solid-state reaction with composition x up to 30%. It is found that with the substitution of Zn2+ for Mg2+ on the B site of the of complex perovskite structure the antiferroelectric (AFE) Curie temperature TC of PMW increases from 40°C (x = 0) to 67°C (x = 30%), indicating an enhancement of antiferroelectric order, whereas, at the same time, the phase transition becomes more diffuse due to a higher degree of chemical inhomogeneity. X-ray diffraction analysis indicates that the crystal structure adopts an orthorhombic space group (Pmcn) with a decrease in lattice parameter a, but an increase in b and c as the Zn 2+ concentration increases. The low dielectric constant (∼ 102), low dielectric loss (tanδ ≈ 10-3), linear-field-induced polarization, and significantly high breakdown field (∼ 125 kV/cm) at room temperature make this family of dielectric materials a promising candidate for ceramic insulators. © 2014 The American Ceramic Society.