Enhanced antiferroelectricity and double hysteresis loop observed in lead-free (1−x)NaNbO₃-xCaSnO₃ ceramics Available to Purchase

Well-defined polarization-electric field double hysteresis loops are rarely observed in pure NaNbO₃ (NN) ceramics due to the metastability of the field-induced ferroelectric phase. In order to stabilize the antiferroelectric phase, various ABO₃-type binary oxides were incorporated into a NaNbO₃ ceramic, where the B-site is occupied with transition elements. In this work, CaSnO₃ was chosen to construct the NaNbO₃-based solid solution by reducing the Goldschmidt tolerance factor and ionic polarizability. X-ray diffraction patterns, transmission electron microscopy images, and Raman spectra indicate enhanced antiferroelectricity. Typical double hysteresis loops were also observed from polarization-electric field measurements in ambient conditions with slightly weakened maximum polarization as the content of CaSnO₃ increased. Our results reveal the generality of this strategy and pave the way for various applications involving high-power energy for NaNbO₃-based ceramics.