Spontaneous Micro-Macro Ferroelectric Domain Switching in PbZrO3-doped Pb(Ni1/3Nb2/3)O3-PbTiO3System

The possibility of the existence of a spontaneous relaxor-normal ferroelectric transition was proposed and examined using 1-3 mol% PbZrO3-doped Pb(Ni1/3Nb2/3)O3-PbTiO3(PNN-PT) systems having tetragonal symmetry at room temperature. On cooling, the system with 60 mol% Pb(Ni1/3Nb2/3)O3underwent a spontaneous transition from a relaxor to a normal ferroelectric state. A microscopic examination demonstrated that the relaxor-normal ferroelectric transition corresponds to a micro-macro domain switching. Long-range ferroelectric domains below the transition temperature were characterized by twinlike 90° macrodomains with tetragonal symmetry. The relaxor-normal transition was further correlated with the rhombohedral-tetragonal first-order phase transition.