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 (Wrec) 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.