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 no...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 Wrec 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.展开更多
基金This work was supported by the National Natural Science Foundation of China(52072028 and 52032007).
文摘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 Wrec 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.
