Effect of rare earth ion doping on the structural, microstructural and diffused phase transition characteristics of BaBi_2Nb_2O_9 relaxor ferroelectrics

摘要

Barium bismuth samarium niobate Ba(Bi_(1-x)Sm_x)_2Nb_2O_9 (x=0, 0.03, 0.05, and 0.10) ceramics have been fabricated successfully via molten salt synthesis route. The X-ray diffraction analysis revealed the existence of bismuth layered perovskite phase with orthorhombic crystal structure in all the compositions studied. The dielectric and electrical conductivity properties were carried out in the 100 Hz to 1 MHz frequency range at 300 K. The dielectric constant and dielectric loss were found to decrease from 186 to 180 and 0.0966 to 0.0755 with increase in samarium content at 100 kHz. A decrease in dielectric constant maximum (ε_m) and a shift in the temperature of dielectric maximum (T_m) from 438 K to 393 K with the increase in the samarium concentration had been observed.