Electrical conductivity study of A-site non-stoichiometric Na 0.5+x Bi 0.5-x TiO 3-δ

In the present work effect of A-site non-stoichiometry on the bulk conductivity of sodium bismuth titanate ceramic is studied. Dense ceramic samples of Na0.5+xBi0.5-xTiO3-δ (x = −0.02, 0.00 and 0.02) were prepared using solid-state reaction route at the sintering temperature of 1150 °C. The XRD results show the formation of rhombohedral phase with R3c symmetry. The electrical studies suggest increase in conductivity with the change in stoichiometry. This increase in the conductivity is associated with the increase in the oxygen vacancies, lattice distortion and defects with the change in stoichiometry.