Ferroelectric and dielectric properties of BiFeO3-Sr0.8Bi2.2Ta2O9 solid solutions

Ferroelectric xBiFeO 3 -(1-x) Sr 0.8 Bi 2.2 Ta 2 O 9 [xBFO-(1-x)SBT] solid solution with x ranging from 0 to 0.4 was synthesized on Pt/Ti/SiO 2 /Si by metalorganic decomposition method. This solid solution system has been found to have a layered perovskite structure and good ferroelectric properties. The remnant polarizations (2Pr) are 9.1 mu C/cm 2 and 7.9 mu C/cm 2 , while coercive field (2Ec) are 196 kV/cm and 209 kV/cm, respectively for 0.2BFO-0.8SBT and 0.4BFO-0.6SBT at an applied field of 300 kv/cm. It is found that increase of BFO concentration decreases the remnant polarization and the dielectric constant, increases the coercive field and the leakage current at certain applied voltage. The highest loss of tangent is observed for 0.8SBT-0.2BFO. It is found that the fatigue properties are decreased when more BFO was added to SBT films. The results were discussed with respect to the effects of Bi 3+ and Fe 3+ in BFO substitution at layered perovskite A and B site of SBT.