Pyroelectric, ferroelectric, piezoelectric and dielectric properties of Na0.5Bi0.5TiO3 ceramic prepared by sol-gel method

Abstract Sodium bismuth titanate (BNT) nanopowder of molar composition 50/50 (Na0.5Bi0.5TiO3) was prepared by a sol-gel processing method. The structure and microstructure of the precursor gel as well as the ferroelectric, pyroelectric, dielectric and piezoelectric properties of the BNT were studied. BNT crystallized in the rhombohedra perovskites structure Na0.5Bi0.5TiO3 was obtained from the precursor gel by heating at 700 °C for 2 h in air. The BNT ceramic at 1100 °C sintering temperature present high crystallinity, good dielectric properties at 1 kHz (e′=885, tan δ=0.03, Tc=370 °C), piezoelectric properties (k33=0.39, c33=105 GPa, e33=12.6 C/m2, d33=120 pC/N), high remnant polarization (Pr=47 μC/cm2) and pyroelectric coefficient ( p =707 μC/m2 K) and low coercive field (Ec=55 kV/cm). Hence, the BNT prepared by sol-gel method could be used for silicon based memory device application where a low synthesis temperature is a key requirement.