Two-Step Ferroelectric to Paraelectric Transition Caused by Peak Aging.

This paper reports a ferroelectric-to-paraelectric (FE-PE) two-step transition in the acceptor-doped ferroelectric systems. In ceramic samples, the DSC peak as well as the dielectric permittivity peak exhibits a split after aging at DSC peak temperature. Such phenomenon also exists in the grain-boundary-free single crystal samples; this excludes the possibility of a grain boundary effect. Moreover, the in-situ optical microscopy observation during heating proves that such peak split is due to a two step FE to PE transition. The microscopic explanation is given based on the symmetry-conforming properties of point defects. [ABSTRACT FROM AUTHOR]