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

A new solid solution of (1-x)Pb(Mg_1/2W_1/2)O ₃-xPb(Zn_1/2W_1/2)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 T_C 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.