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

Nanocrystallites of relaxer ferroelectric composition in the system of 0.54 Pb(Zn1/3Nb2/3)O-3-0.36Pb(Mg1.3Nb2/3)O-3-0.1PbTiO(3) (PZN-PMN-PT) were trigg ered to form in mixed oxides of PbO, ZnO, MgO, Nb2O5 and TiO2 by an increas ing degree of mechanical activation at room temperature. They exhibited a n anocrystalline perovskite structure, as indicated by the phase analysis usi ng X-ray diffraction. Transitional pyrochlore and PT phases, which have com monly been observed in the solid state reaction of constituent oxides at hi gh temperatures, were not observed during mechanical activation prior to fo rmation of the perovskite phase. This suggests that the one or more interfa cial diffusions and reactions that occur in the conventional solid state re action are not responsible for the phase formation triggered by mechanical activation at room temperature. The activation-derived PZN-PMN-PT powder wa s highly sintering-reactive and it was sintered to > 99% theoretical densit y at 1100 degrees C for 1 h. Sintered PZN-PMN-PT demonstrated a maximum die lectric constant of similar to 19 000 and a dielectric loss of 0.015 at the Curie temperature of 103 degrees C when measured at 1 kHz. (C) 2000 Elsevi er Science S.A. All rights reserved.