Perovskite formation, dielectric and ferroelectric properties ofPbZrO3–Pb(Ni1/3Nb2/3)O3 ceramics via a columbite precursor synthetic route

Abstract

Perovskite structures in the PZ–PNN system with formula(1−x)PbZrO3–xPb(Ni1/3Nb2/3)O3 with x = 0.0–0.5 are synthesized via the columbite precursor technique. The formation of the perovskitephase in the calcined powders has been investigated as a function of calcination conditions byusing thermogravimetric and differential thermal analysis (TG-DTA) and x-ray diffraction(XRD) techniques. The complete solid solutions of the perovskite phase of PZ–PNN ceramicswere obtained over a wide compositional range. It was observed that for the binary system(1−x)PbZrO3–xPb(Ni1/3Nb2/3)O3, thechange in the calcination temperature is approximately linear with respect to the PNN content in the rangex = 0.0–0.5. Withincreasing x, the calcination temperature shifts forward to high temperatures. It is seen that optimization ofthe calcination conditions can lead to a 100% yield of PZ–PNN in a pseudo-cubic phase. TheP–E hysteresis loop measurements demonstrated that the ferroelectric properties of the ceramics in thePZ–PNN system changed gradually from normal ferroelectric behavior to relaxor ferroelectricbehavior with increasing PNN concentration. In addition, the squareness of the hysteresis loop(Rsq) decreased quasi-linearly as the molar fraction of PNN increased. The maximum spontaneous polarization(Ps) and remanentpolarization (Pr) for the x = 0.1 composition were 31.6 µC cm−2 and 27.8 µC cm−2, respectively. These results clearly show the significance of PNN in controlling theelectrical responses of the PZ–PNN system.