Nanocrystalline 0.54PZN–0.36PMN–0.1PT of perovskite structure by mechanical activation

Nanocrystallites of relaxor ferroelectric composition in the system of 0.54Pb(Zn1/3Nb2/3)O3–0.36Pb(Mg1/3Nb2/3)O3–0.1PbTiO3 (PZN–PMN–PT) were triggered to form in mixed oxides of PbO, ZnO, MgO, Nb2O5 and TiO2 by an increasing degree of mechanical activation at room temperature. They exhibited a nanocrystalline perovskite structure, as indicated by the phase analysis using X-ray diffraction. Transitional pyrochlore and PT phases, which have commonly been observed in the solid state reaction of constituent oxides at high temperatures, were not observed during mechanical activation prior to formation of the perovskite phase. This suggests that the one or more interfacial diffusions and reactions that occur in the conventional solid state reaction are not responsible for the phase formation triggered by mechanical activation at room temperature. The activation-derived PZN–PMN–PT powder was highly sintering-reactive and it was sintered to >99% theoretical density at 1100°C for 1 h. Sintered PZN–PMN–PT demonstrated a maximum dielectric constant of ∼19 000 and a dielectric loss of 0.015 at the Curie temperature of 103°C when measured at 1 kHz.