Effect of dysprosium substitution on the electrical properties of SrBi4Ti4O15 ceramics

The four-layer Aurivillius compound SrBi4-xDyxTi4O15 (x = 0.02 - 0.1) was synthesized by using a solid state sintering method. X-ray diffraction (XRD) analysis revealed that the dysprosium-substituted SrBi4Ti4O15 ceramics have a pure four-layer Aurivillius-type structure. The lattice parameters and densities were calculated with XRD studies. The experimental densities obtained were about 95% that of theoretical values. The effects of dysprosium oxide on the microstructure, ferroelectric, dielectric and piezoelectric properties of the ceramics were investigated. The dielectric constant of Dy-doped samples was found to decrease with increasing Dy content. At x = 0.06, the piezoelectric charge coefficient (d33) and the electromechanical coupling factor (kp) were found to be maximum. (paper)