Effect of acceptor and donor dopants (Na, Y) on the microstructure and dielectric characteristics of high Curie point PZT-modified ceramics

Abstract

This study describes the preparation of a solid solution of $${\text{Pb}}^{2 + } [({\text{Zr}}_{0.05}^{4 + } ,{\text{Ti}}_{0.95}^{4 + } )_{0.97} ({\text{Al}}_{1/3}^{3 + } ,{\text{Zn}}_{1/2}^{2 + } ,{\text{W}}_{1/3}^{6 + } )_{0.03} ]{\text{O}}_{3}$$ (PZT) based on the mixed oxide method. A different amount of sodium carbonate and yttrium oxide (0.03 at.%, 0.06 at.%, and 0.1 at.%), where the ratio of Na:Y = 1:1 by mole, was added to PZT to investigate the effect of Na and Y co-doping. The ceramic samples were sintered and then subjected to phase identification, physical properties determination, and dielectric properties measurement. It was assumed that, by integrating into the lattice parameters, there is a substitution preference alternation of Y3+ for host cations in the perovskite lattice, while Na+ replaces the A-position of Pb2+ in the lattice. This resulted in more oxygen vacancy being generated in the lattice. PZT–xNY compositions exhibited an obvious anomaly in the temperature dependence of dielectric loss and dielectric permittivity below the phase transition temperature. In addition, it was found that doping of 0.1 at.% Na and Y resulted in a maximum dielectric constant (ec$$\sim 10,400$$) at Curie temperature (~ 749 K) with dissipation factor tan(δ)$$\sim 2.798$$%. Moreover, the diffusivity estimated using the modified Curie–Weiss law obtained at 1 kHz for all compositions showed that the material exhibits a diffuse-type phase.