Piezoelectric ceramics Na1−xBaxNb1−xTixO3 with low BaTiO3 concentrations x have been prepared by the solid‐state reaction method, and their ferroelectric and piezoelectric properties have been studied. The ceramics are classic ferroelectrics when x≤0.10, and the ferroelectric–paraelectric phase transition becomes diffusive when x≥0.15. A low doping level of BaTiO3 changes the NaNbO3 ceramics from antiferroelectric to ferroelectric. With the increase in BaTiO3 doping level, the Curie temperature of ceramics decreases linearly and the remnant polarization and coercive field also decrease, while their dielectric constant increases. Na0.9Ba0.1Nb0.9Ti0.1O3 ceramics show the largest piezoelectric constant d33 (147 pC/N) and good sinterability, suggesting that it is a good candidate for lead‐free piezoelectric ceramics.

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Large plate-like Na 0.5 Bi 0.5 TiO 3 (NBT) templates have been successfully synthesized from bismuth layer-structured ferroelectric Na 0.5 Bi 4.5 Ti 4 O 15 (NBIT) particles by the topochemical method. Because of the highly anisotropic structure, plate-like NBIT particles were first synthesized by the molten-salt process. After the topochemical reaction with the complementary reactants (Na 2 CO 3 , and TiO 2 ) in NaCl flux, the layer-structured NBIT particles were transformed to the perovskite NBT templates. The resulting NBT templates are large and of plate-like shape. Our results also reveal that they are more effective in inducing grain orientation in the BNKT-BT ceramics as compared with BIT templates. For a BNKT-BT ceramic textured with 20 wt% of NBT templates, it exhibits a very high degree of grain orientation and gives a large Lotgering factor of 0.89. J ournal

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molten salt synthesis. As the structures of NBT and NBiT are similar, the NBiT particles can be transformed to Textured Bi05Na035K01Li005TiO3 (BNKLT) ceramics plate-like NBT templates by a topochemical reaction. In have been fabricated by a Reactive Templated Grain the present works, NBT templates, which were Growth (RTGG) method using plate-like Na0.5Bi0.5TiO3 synthesized from NBiT particles through the (NBT) templates. The NBT templates were synthesized topochemcial transformation, were used to fabricate from bismuth layer-structured ferroelectric textured Bi0.5Na0.35K0.1Li0.05TiO3 (BNKLT) ceramics Na0.5Bi4.5Ti4O15 (NBiT) particles by the topochemical using a tape casting method. The dielectric and method. After reactively sintering at 1085°C for 12h, the piezoelectric of the textured ceramics were studied and ceramic textured with 20wt% NBT templates contains a correlated with the grain orientation. large fraction of grains aligned with their a-axis normal to the sample surface, giving a Lotgering factor of 0.6. EXPERIMENTALThe piezoelectric properties were improved while depolarization temperature remained almost unchanged.Plate-like NBiT particles were synthesized by the The piezoelectric coefficient d33 of the ceramic reaches a molten salt method using commercially available metal high value of 300 pC/N, while the electromechanical oxides or carbonate powders: Bi2O3 (International coupling coefficients kp and kt are 0.39 and 0.56, Laboratory, San Bruno, CA, 990/O), Na2CO3 respectively. (International Laboratory, 990/O) and TiO2 (International Laboratory, 990 o). The powders were weighted according