Dielectric behaviors and phase separation in Pb(Ni1/2W1/2)O3–PbTiO3

Relaxor ferroelectric phases of Pb(Ni1/2W1/2)O3–PbTiO3 (PNW–PT) near the morphotropic boundary composition (MPB) were synthesized by sintering of the perovskite nanocrystallites derived from mechanical activation of constituent oxides. They demonstrate unique temperature stability in dielectric behavior over the wide temperature range of −80 to 60 °C, when sintered at 970 °C. Their dielectric behavior is strongly dependent on the sintering schedule and subsequent annealing at relatively low temperatures, due to phase segregation and evolution of compositional inhomogeneity, as confirmed by Raman spectroscopy and compositional mapping.