Strategy for stabilization of the antiferroelectric phase (Pbma) over the metastable ferroelectric phase (P21ma) to establish double loop hysteresis in lead-free (1−x)NaNbO3-xSrZrO3 solid solution

Abstract

A new lead-free antiferroelectric solid solution system, (1−x)NaNbO3-xSrZrO3, was rationalized through noting the crystal chemistry trend, of decreasing the tolerance factor and an increase in the average electronegativity of the system. The SrZrO3 doping was found to effectively stabilize the antiferroelectric (P) phase in NaNbO3 without changing its crystal symmetry. Preliminary electron diffraction and polarization measurements were presented which verified the enhanced antiferroelectricity. In view of our recent report of another lead-free antiferroelectric system (1−x)NaNbO3-xCaZrO3 [H. Shimizu et al. “Lead-free antiferroelectric: xCaZrO3 - (1−x)NaNbO3 system (0 ≤ x ≤ 0.10),” Dalton Trans. (published online)], the present results point to a general strategy of utilizing tolerance factor to develop a broad family of new lead-free antiferroelectrics with double polarization hysteresis loops. We also speculate on a broad family of possible solid solutions that could be identified and tested for this important type of dielectric.