Tailoring and improving the strong-electric-field electrical properties of the BNT-BT ferroelectric ceramics by a functional-group-doping

Abstract Lead-free ferroelectric ceramics with high tailored strong-electric-field electrical properties (energy storage, electrocaloric cooling, and energy harvesting, etc.) are attractive to many fields, such as modern electronics, medical and military, etc. We demonstrated that the strong-electric-field electrical properties of the 0.89(Bi0.5Na0.5TiO3)-0.11(BaTiO3) (BNT-BT) relaxor ceramics not only could be tailored easily after doping the (BaTiO3)0.5-(BiMg0.5Ti0.5O3)0.5 (BT-BMT, the functional-group), but also could be improved largely. As a result, an optimized electrostrain (S ~ 0.4%) was acquired at x = 0.12, and an optimized energy storage density (W ~ 0.775 J/cm3) with a high efficiency (η ~ 50%) was achieved at x = 0.24, as well as a phase-induced negative electrocaloric (EC) effect (ΔT ~ 3.72 K) was harvested at x = 0.04. It is concluded that the functional-group-doping can be regarded as a new strategy to tailor and improve the strong-electric-field electrical properties of ferroelectric materials.