Modification of dielectric relaxations in sodium bismuth titanate with samarium doping

Na0.5Bi(0.5−x) SmxTiO3 (NBST) ceramics with x=0.05x=0.05, 0.1, and 0.15 are prepared through chemical route. The X-ray diffraction studies confirmed the formation of single phase. Dielectric measurements in the temperature region ranging from room temperature (∼30 °C) to 600 °C at different frequencies (10 kHz–1 MHz) showed anomalies at 130, 306, and 474 °C (at 10 kHz frequency) for x=0.05x=0.05 sample. Other samples showed only two peaks. To establish the electrical nature of these relaxations, impedance measurements are done at different temperatures and frequencies. The relaxation time, obtained from both impedance and modulus data, is found to decrease with increase in temperature. The relaxations observed are of non-Debye type. Increase in samarium content increases the activation energy for relaxation.