COMPOSITIONAL DEPENDENCE OF ELECTRICAL PROPERTIES IN LA AND NB CO-MODIFIED Sr0.8Bi2.2Ta2O9 THIN FILMS

ABSTRACT Sr0.8La0.1Bi2.1Ta2O9 thin films with different concentration of Nb at the Ta-site were grown on Pt/Ti/SiO2/Si substrates using metalorganic decomposition method. The composition dependence of the electric properties of them was investigated. It is found that the remanent polarization increases when the Nb concentration peaks around 0.3. However, the coercive field doesn't increase monotonously but peaks around 0.2 and 0.3. At the applied electric field of 300 kV/cm, the remanent polarization (2Pr) values of Sr0.8La0.1Bi2.1(Ta0.8Nb0.2)2O9, and Sr0.8La0.1Bi2.1(Ta0.75Nb0.25)2O9 as well as Sr0.8La0.1Bi2.1(Ta0.7Nb0.3)2O9 film were 25 μ C/cm2, 24 μ C/cm2 and 35 μ C/cm2, respectively. The coercive field (2Ec) value were 204 kV/cm, 112 kV/cm and 197 kV/cm for Sr0.8La0.1Bi2.1(Ta0.8Nb0.2)2O9, Sr0.8La0.1Bi2.1(Ta0.75Nb0.25)2O9 and Sr0.8La0.1Bi2.1(Ta0.7Nb0.3)2O9, respectively.