Structural evolution and electrical properties of BaTiO₃ doped with Gd3

BaTiO₃ doped with Gd3+ (Ba1-xGdxTi1-x/4O3) was synthesized using the solid-state reaction method with x = 0.001, 0.003, 0.005, 0.01, 0.05, 0.1, 0.15, 0.20, 0.25, 0.30, and 0.35 Gd3+ (wt. %). The powders were decarbonated at 900 °C and sintered at 1400 °C for 8 hours. The tetragonality of the synthesized Gd3+-doped BaTiO₃ particles was analyzed. XRD patterns and Raman spectra revealed that the crystal phase of the obtained particles was predominately tetragonal BaTiO₃; the intensity of the Raman bands at 205 cm-1, 265 cm-1, and 304 cm-1 decreased when Gd3+ was increased. A secondary phase (Gd2Ti2O7) was found when the Gd3+ content was higher than 0.15 wt. %. The capacitance of the sintering pellets was measured at 1 kHz; these values were used to calculate the relative permittivity, the maximum permittivity values were recorded for the samples with x = 0.001, 0.005, and 0.1.