A-site substitution-controlled dielectric dispersion in lead-free sodium bismuth titanate.

Effect of doping in Na0.5Bi0.5TiO3 (NBT) with Ce3+ and Sm3+ at the A-site on dielectric behaviour, impedance and conductivity is being reported. Na0.5Bi0.5-xAxTiO3 samples (A being Ce and Sm) are studied with varying values of x. For Na0.5Bi0.5-xCexTiO3 samples x is 0.001, 0.005 and 0.007 and for Na0.5Bi0.5-xSmxTiO3 samples x is 0.05, 0.1 and 0.15. Dielectric constant and loss are studied in the frequency range 10 kHz to 1 MHz and in the temperature range 30-650°C. Impedance and electric modulus studies are undertaken. The relaxations observed in the samples are non-Debye and activation energies for relaxation and conduction are evaluated. [ABSTRACT FROM AUTHOR]