Effect of Ca substitution sites on dielectric properties and relaxor behavior of Ca doped barium strontium titanate ceramics

Microstructure, dielectric properties, and ferroelectric relaxor behavior of Ca doped barium strontium titanate (BSCT) ceramics prepared by solid-state reaction were investigated. It was demonstrated that the unit cell volume of the BSCT ceramics firstly decreases with the increase of Ca contents up to x = 0.08, but increases with further addition of Ca (x a parts per thousand yen 0.12). The shrinkage of the unit cell volume resulted from the substitution of Ba2+ by Ca2+ when x a parts per thousand currency sign 0.08, which enhanced the relaxor behavior of the ferroelectrics. Conversely, a small amount of Ca2+ substituted for Ti4+ site when x a parts per thousand yen 0.12, which weakens the relaxor behavior of the BSCT ceramics. The 8 mol % doped BSCT ceramic yielded the maximum index of relaxation (gamma) of 1.90 and made it a promising candidate for future industrial application of efficient and eco-friendly relaxor ferroelectric materials.