FERROELECTRIC, PIEZOELECTRIC AND DIELECTRIC PROPERTIES OF Nb MODIFIED Bi4Ti3O12-SrBi4Ti4O15 INTERGROWTH

ABSTRACT Doping and constructing intergrowth are found to be an effectual approach to modify the electrical properties of bismuth layer-structured ferroelectrics. In this work, ferroelectric, piezoelectric and dielectric properties of Nb-doped Bi4Ti3O12-SrBi4Ti4O15 (BTN-SBTN-x) intergrowth ceramics were investigated. The ferroelectric property of Bi4Ti3O12-SrBi4Ti4O15 was improved by niobium doping. The remanent polarization (2P r ) increases at first, then decreases with the increase of niobium content, while the coercive field changes little with Nb-doping. As niobium content is 0.06, the 2P r maximizes at a value of 34.9 μC/cm2, which is increased by about 75% in comparison with that of Bi4Ti3O12-SrBi4Ti4O15 (2P r = 20.0 μC/cm2). The Curie temperature of the samples varies hardly upon Nb-doping, which indicates that the good thermal stability of Bi4Ti3O12-SrBi4Ti4O15 is not deteriorated after Nb addition. Piezoelectric coefficient d33 was increased from 9.3 pC·N−1 to 18.6 pC·N−1 due to the enlargement ...