Ferroelectric and piezoelectric properties of Na_1-xBa_xNb_1-xTi_xO₃ceramics

Piezoelectric ceramics Na1-xBaxNb1-xTixO3with low BaTiO3concentrations 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 BaTiO3changes the NaNbO3ceramics from antiferroelectric to ferroelectric. With the increase in BaTiO3doping level, the Curie temperature of ceramics decreases linearly and the remnant polarization and coercive field also decrease, while their dielectric constant increases. Na0.9Ba0.1Nb0.9Ti0.1O3ceramics show the largest piezoelectric constant d33(147 pC/N) and good sinter-ability, suggesting that it is a good candidate for lead-free piezoelectric ceramics.