Study of (Sr, Pb)TiO3 ceramics on dielectric and physical properties

(Sr_1−xPb_x)TiO₃ (x=0.2, 0.25 and 0.3) ceramics were prepared by the conventional mixed oxide method. Their dielectric permittivity, and loss tangent values were measured with and without DC bias field, thermal expansion and microstructure were observed. Three compositions showed similar Curie–Weiss constant, ca. 1×10⁵°C and thermal expansion coefficient, 10×10⁻⁶°C⁻¹. Transition temperatures of the compositions were, −60, −25 and 10°C, respectively, with loss tangent values of less than 0.1% measured at room temperature and at 10 kHz. Dielectric tunabilities of, 3, 15, and 70% were measured on x=0.2, 0.25 and 0.3 under 20 kV/cm bias field at 10 kHz and at room temperature.