Effect of modified two-step sintering approaches on potassium tantalum niobate-barium titanate (KTN-BT) ceramics and their dielectric and piezoelectric properties

Abstract

The Potassium Tantalum Niobate-Barium Titanate (KTN-BT) solid solution system ceramics with the composition 0.02K(Ta0.5Nb0.5)O3-0.98BaTiO3 were prepared by a two-step sintering mechanism, for different sintering durations. Crystalline and microstructure analyses of the prepared samples were performed. Dielectric and piezoelectric properties were also investigated. Moreover, apparent piezoelectric constant d33 was measured using the slope of strain vs. electric field curves for these ceramics. It was observed that the high values of density, electrical conductivity, relative dielectric permittivity (εr = 3615.983), piezoelectric coefficient (d33 = 315 pm/V) and remnant polarization (Pr = 9.53 µC/cm2) were obtained for ceramics prepared through a new variation of the conventional two-step sintering method. Finally, the relationship between sintering mechanism, microstructure and piezoelectricity was discussed for the 0.02K(Ta0.5Nb0.5)O3-0.98BaTiO3 ceramics.