Processing and characterization of Ba-based layered ferroelectric relaxors

摘要

Ceramics with compositions belonging to the so-called Aurivillius oxides, SrBi{sub}2Ta{sub}2O{sub}9 (SET) and BaBi{sub}2Ta{sub}2O{sub}5 (BBT) as well as their solid solutions, Sr{sub}(1-x)Ba{sub}xBi{sub}2Ta{sub}2O{sub}9 (x=0-1) have been prepared by conventional mixed oxide route. Processing parameters for the fabrication of high-quality dense samples were optimized. SET and BBT exhibited unlimited mutual solubility as revealed by X-ray diffraction studies. The substitution of strontium in SBT by barium induces the shift of Curie temperature to lower values while introducing a frequency dispersion in the temperature dependence of its dielectric behavior. Strongly non-linear dependence of the temperature of dielectric maximum is observed.