Spontaneous Micro-Macro Ferroelectric Domain Switching in PbZrO₃-doped Pb(Ni_1/3Nb_2/3)O₃-PbTiO₃System

Abstract

The possibility of the existence of a spontaneous relaxor-normal ferroelectric transition was proposed and examined using 1-3 mol% PbZrO 3 -doped Pb(Ni 1/3 Nb 2/3 )O 3 -PbTiO 3 (PNN-PT) systems having tetragonal symmetry at room temperature. On cooling, the system with 60 mol% Pb(Ni 1/3 Nb 2/3 )O 3 underwent 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.