Symmetry of high-piezoelectric Pb-based complex perovskites at the morphotropic phase boundary I. Neutron diffraction study on Pb(Zn1/3Nb2/3)O3 -9%PbTiO3

摘要

The symmetry was examined using neutron diffraction method onPb(Zn1/3Nb2/3)O3 -9%PbTiO3 (PZN/9PT) which has a composition at themorphotropic phase boundary (MPB) between Pb(Zn1/3Nb2/3)O3 and PbTiO3. Theresults were compared with those of other specimens with same composition butwith different prehistory. The equilibrium state of all examined specimens isnot the mixture of rhombohedral and tetragonal phases of the end members butexists in a new polarization rotation line Mc# (orthorhombic-monoclinic line).Among examined specimens, one exhibited tetragonal symmetry at room temperaturebut recovered monoclinic phase after a cooling and heating cycle.