Structural and electrical properties of 1 − x(Na0.5K0.5)NbO3–x(Sr0.5Ca0.5)TiO3 ceramics

In this study, 1 − x(Na0.5K0.5)NbO3–x(Sr0.5Ca0.5)TiO3 ceramics were fabricated using the conventional mixed oxide method. The effects of the addition of (Sr0.5Ca0.5)TiO3 on the structural and electrical properties of the specimens were investigated for their application in piezoelectric devices. As the results of X-ray diffraction analysis show, all specimens display the typical polycrystalline perovskite structure without the presence of the second phase. Sintered densities increased with an increase in the amount of (Sr0.5Ca0.5)TiO3 added and the specimen with 0.08 mol% of (Sr0.5Ca0.5)TiO3 added showed the maximum value of 4.54 g/cm3. Both average grain size and densification increased with an increase in the amount of (Sr0.5Ca0.5)TiO3. The electromechanical coupling factor, dielectric constant ϵr, dielectric loss tan δ, d33 and Curie temperature of the 0.92(Na0.5K0.5)NbO3–0.08(Sr0.5Ca0.5)TiO3 specimens doped with 0.08 mol% of (Sr0.5Ca0.5)TiO3 were 0.31, 1338, 0.021, 138 and 445 °C, respectively.