Wang Ziyang,Chen Peng,Shi Wenjing,Li Yang,Li Dequan,Zhang Leiyang,Yan Yan,Wang Yifei,Peng He,Li Quan,Liu Gang
In the current investigation, the CuO modified BaTiO 3 ceramics were prepared through the conventional electroceramic processing. XRD, XPS, and SEM have been employed to characterize the phases, valences of ions and the microstructures. The sintering behaviors of the prepared samples were performed using a dilatometer, and ceramics could be fabricated at lower temperature. The electric field and temperature dependent energy storage performance have been studied. The introducing of CuO is very effective to improve the energy storage density and the efficiency due to the formed double P-E loops. 0.5 wt.% CuO modified ceramic exhibited an energy density of 0.52 J/cm 3 , which is nearly twice of pure BaTiO 3 ceramic. The J-E loops of CuO modified samples indicated double domain switches, consistent with the double P-E loops.
Yang Yin,Jing-Ru Yu,Yu-Cheng Tang,Ai-Zhen Song,Huan Liu,Dong Yang,Jing-Feng Li,Lei Zhao,Bo-Ping Zhang
NaNbO 3 -based ceramics usually show ferroelectric-like P-E loops at room temperature due to the irreversible transformation of the antiferroelectric orthorhombic phase to ferroelectric orthorhombic phase, which is not conducive to energy storage applications. Our previous work found that incorporating CaHfO 3 into NaNbO 3 can stabilize its antiferroelectric phase by reducing the tolerance factor ( t ), as indicated by the appearance of characteristic double P-E loops. Furthermore, a small amount of MnO 2 addition effectively regulate the phase structure and tolerance factor of 0.94NaNbO 3 -0.06CaHfO 3 (0.94NN-0.06CH), which can further improve the stability of antiferroelectricity. The XRD and XPS results reveal that the Mn ions preferentially replace A-sites and then B-sites as increasing MnO 2 . The antiferroelectric orthorhombic phase first increases and then decreases, while the t shows the reversed trend, thus an enhanced antiferroelectricity and the energy storage density W rec of 1.69 J/cm 3 at 240 kV/cm are obtained for 0.94NN-0.06CH-0.5%MnO 2 (in mass fraction). With the increase of Mn content to 1.0 % from 0.5 %, the efficiency increases to 81 % from 45 %, although the energy storage density decreases to 1.31 J/cm 3 due to both increased tolerance factor and non-polar phase.