Bi_(0.44)Na_(0.50)Ba_(0.06)TiO_(3-δ)与Bi_(0.50)Na_(0.44)Ba_(0.06)TiO_(3+δ)无铅陶瓷的显微结构、介电及铁电性能

Microstructure,dielectric and ferroelectric properties of Bi_(0.44)Na_(0.50)Ba_(0.06)TiO_(3)-δand Bi_(0.50)Na_(0.44)Ba_(0.06)TiO_(3+δ)lead-free ceramics

采用常规固相法制备Bi_(0.44)Na_(0.50)Ba_(0.06)TiO_(3-δ)与Bi_(0.50)Na_(0.44)Ba_(0.06)TiO_(3+δ)无铅陶瓷,在不同温度烧结了两类陶瓷,对比分析了两类陶瓷的晶体结构、显微组织、介电和铁电性能。结果发现1150℃烧结的两类陶瓷具有纯钙钛矿结构,致密性良好,相对密度高于97%。介电测试结果表明两类陶瓷的介温谱存在显著差别,其中Bi_(0.44)Na_(0.50)Ba_(0.06)TiO_(3-δ)陶瓷的介电常数随温度升高显著增大,两类陶瓷均在居里温度附近呈现弥散相变特征。铁电性能测试表明:Bi_(0.44)Na_(0.50)Ba_(0.06)TiO_(3-δ)陶瓷的最大极化强度、剩余极化强度和矫顽场值分别为34.1μC/cm 2、28.5μC/cm 2和53.7 kV/cm;Bi_(0.50)Na_(0.44)Ba_(0.06)TiO_(3+δ)陶瓷的相应值分别为42.8μC/cm 2、31.8μC/cm 2和48.2 kV/cm,说明Bi_(0.50)Na_(0.44)Ba_(0.06)TiO_(3+δ)陶瓷具有更佳的铁电性能。

The lead-free ceramics Bi_(0.44)Na_(0.50)Ba_(0.06)TiO_(3-δ)and Bi_(0.50)Na_(0.44)Ba_(0.06)TiO_(3+δ)were prepared via the conventional sintering method.The two kinds of ceramics were sintered at various temperatures.Their crystallite structure,microstructure,dielectric and ferroelectric properties were studied comparatively.The ceramics sintered at 1150℃have pure perovskite structure and dense microstructure with relative densities higher than 97%.The dielectric measurement shows that the dielectric spectra are different from each other obviously.Dielectric constant of the Bi_(0.44)Na_(0.50)Ba_(0.06)TiO_(3-δ)ceramics increases greatly with increasing temperature.The two kinds of ceramics show diffuse phase transition character.The values of maximum polarization,remanent polarization,and coercive field are 34.1μC/cm 2,28.5μC/cm 2 and 53.7 kV/cm for Bi_(0.44)Na_(0.50)Ba_(0.06)TiO_(3-δ).The corresponding values are 42.8μC/cm 2,31.8μC/cm 2 and 48.2 kV/cm for Bi_(0.50)Na_(0.44)Ba_(0.06)TiO_(3+δ).The ceramics Bi_(0.50)Na_(0.44)Ba_(0.06)TiO_(3+δ)shows better ferroelectric properties.