Achieving high ordering degree of B-site cations in Pb(Sc_0.5Ta_0.5)O₃ perovskite ferroelectric ceramics

Perovskite relaxor ferroelectrics generally possess a microstructural feature, that is, different cations occupying a chemically equivalent position. The ordering degree of these cations is a critical factor for macroscopic properties of relaxor ferroelectrics. Pb(Sc_0.5Ta_0.5)O₃ is a classical relaxor ferroelectric and tuning its B-site ordering degree is of particular interest over years. In this work, we propose a method to directly control the ordering degree of Pb(Sc_0.5Ta_0.5)O₃ ceramics during the sintering process by regulating the content of compensated Pb₃O₄ powder. It is found that the B-site ordering degree is closely related to the lead vacancies in Pb(Sc_0.5Ta_0.5)O₃ ceramics. This work may shed a light on the design of relaxor ferroelectrics with desired B-site ordering degree.