Evolution of dielectric and ferroelectric relaxor states in Al3+-doped BaTiO3

Abstract

In ferroelectric BaTiO3, we report the evolution of the Dielectric Relaxor and Ferroelectric Relaxor states as a function of B-site doped Al3+ concentration. The relaxor states occur after the paraelectric-ferroelectric phase transition upon cooling. Two different mechanisms are proposed; one based on migration of oxygen vacancies for symmetry-confirmation and the other based on disruption of long-range ferroelectric order by high concentrations of Al3+ ions at the B-site.