Structural, electrical and piezoelectric properties of nanocrystalline tin-substituted barium titanate ceramics

Abstract

Barium stannate titanate Ba(Ti 1− x Sn x )O 3 ceramics with x = 0, 0.025, 0.045 and 0.065 were synthesized using nanocrystalline powders of about 86-nm particle size. The effects of the increasing Sn content on the dielectric, polarization, strain and piezoelectric behavior of the ceramics were studied. In the range of composition studied, an increase in Sn concentration causes the Curie temperature ( T c ) to decrease from 115 °C to 45 °C and the phase transition to become more diffuse. Increasing Sn content in the ceramics produces decrease in remnant polarization ( P r ) from 5.2 μC/cm 2 to 0.3 μC/cm 2 and coercive field ( E c ) from 4.6 kV/cm to 0.8 kV/cm. The unipolar strain level of ∼0.097% for x = 0 gradually decreases to ∼0.027% as the value of x increases to 0.065. The electromechanical coupling factor k p and the piezoelectric charge constant d 33 also show gradual decline from 41.2% to 19.3% and 183 pC/N to 4 pC/N respectively as the Sn content in the ceramics increases.