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

Large strain response based on relaxor-antiferroelectric coherence in Bi0.5Na0.5TiO3-SrTiO3-(K0.5Na0.5)NbO3 solid solutions A new lead-free antiferroelectric solid solution system, (1Àx)NaNbO 3 -xSrZrO 3 , was rationalized through noting the crystal chemistry trend, of decreasing the tolerance factor and an increase in the average electronegativity of the system. The SrZrO 3 doping was found to effectively stabilize the antiferroelectric (P) phase in NaNbO 3 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 (1Àx)NaNbO 3 -xCaZrO 3 [H. Shimizu et al. "Lead-free antiferroelectric: xCaZrO 3 -(1Àx)NaNbO 3 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. V C 2015 AIP Publishing LLC. [http://dx.

Ultrahigh Energy‐Storage Density in NaNbO3‐Based Lead‐Free Relaxor Antiferroelectric Ceramics with Nanoscale Domains

“…NaNbO 3 (NN) as a lead‐free AFE material has recently received resurgent attention for energy‐storage applications . However, its AFE P phase with a Pbma space group is not stable at room temperature (RT) and tends to irreversibly transform to FE phase in response to a large external electric field.…”

“…However, its AFE P phase with a Pbma space group is not stable at room temperature (RT) and tends to irreversibly transform to FE phase in response to a large external electric field. Many attempts have been focused on how to stabilize the AFE phase at RT by doping other ABO 3 perovskite phases or improving the fabrication process as the antiferroelectricity of NN depends on the grain size, density, and defects . Some NN‐based solid solutions were reported to exhibit stable AFE orthorhombic P phase at RT, yet extremely large phase switching hysteresis was observed, in addition to their relatively low E B and W rec .…”

Stabilized antiferroelectricity in xBiScO3-(1-x)NaNbO3 lead-free ceramics with established double hysteresis loops

“…NaNbO 3 has an AFE P (space group Pbma) phase at ambient conditions; [5][6][7][8][9] however, the double hysteresis loops are rarely observed in NaNbO 3 due to the existence of a metastable ferroelectric (FE) Q (space group P2 1 ma) phase. [10][11][12][13][14][15][16] It is further noted that a stabilized AFE phase requires a lower tolerance factor (t). [16][17][18][19][20][21] The calculation of the Goldschmidt tolerance factor in an ABO 3type perovskite is shown in Eq.…”

“…It has been experimentally observed that the polar order can be tuned into antipolar order by decreasing the t. The lead-free BiFeO 3 is a good example; the polar R3c phase was transformed into a PbZrO 3 -like antipolar phase after adding rare earth elements to lower t. [23][24][25] It was found that the rule could also be applied to NaNbO 3 , and we predicted a broad range of different solid solution compositions that should host the AFE behavior. Recently, our group has demonstrated that AFE behavior could be obtained by adding CaHfO 3 , 10 SrZrO 3 , 11 and CaZrO 3 , 12,15 which can effectively decrease the tolerance factor and then stabilize the AFE phase in NaNbO 3 . The observed zone axis electron diffraction patterns and electric field induced signature AFE double hysteresis P-E loops verified the validity for the NaNbO 3 material system.…”

Lead-free piezoceramics: Status and perspectives

“…The new insight, notably of bismuth-based perovskites, has spawned new research fields into oxygen conductors, 33 high-temperature dielectrics, 34 and energy-storage materials. 35 Similarly, a greater understanding of niobate-based materials has yielded the development of new antiferroelectric niobates for energy storage 36 and for electrocalorics. 37 …”