New Antiferroelectric Solid Solution of Pb(Mg1/2W1/2)O3-Pb(Zn1/2W1/2)O3 as Dielectric Ceramics

A new solid solution of (1-x)Pb(Mg1/2W1/2)O3-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 degrees C (x=0) to 67 degrees 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 Zn2+ concentration increases. The low dielectric constant (similar to 102), low dielectric loss (tan approximate to 10-3), linear-field-induced polarization, and significantly high breakdown field (similar to 125kV/cm) at room temperature make this family of dielectric materials a promising candidate for ceramic insulators.