Effect of Lu doping on the structure, electrical properties and energy storage performance of AgNbO3 antiferroelectric ceramics

Abstract

Recently, AgNbO₃ antiferroelectric ceramics have attracted great attention by virtue of their characters of high energy storage density and environmental friendliness. To further optimize the electrical properties, in this work, Lu₂O₃ modified AgNbO₃ ceramics were prepared via conventional solid state method. Crystal structure and element analysis indicated the Lu³⁺ ion preferred to enter the A-site when Lu₂O₃ content was lower than 2 mol%, otherwise, it was more likely to form LuNbO₄ or Lu₃NbO₇-based solid solutions. Remarkably improved stability of antiferroelectric phase was observed once Lu³⁺ ions enter into the A-site, on account of the decrease of cell volume and tolerance factor. As a consequence, an enhanced recoverable energy storage density (W_rec) of 3.5 J/cm³ was achieved in 1 mol% Lu₂O₃ modified AgNbO₃ ceramics at 210 kV/cm, which is superior to the other lead-free ceramics under moderate electric field (< 220 kV/cm). It is believed our study will provide a good reference for the development of AgNbO₃-based dielectric capacitors.