纳米BaTiO3的制备、掺杂及介电性能研究

Preparation, Doping and Dielectric Properties of Nanomter-sized Barium Titanate Powder

采用共沉淀法制备了纳米钛酸钡粉体,并运用XRD和SEM对产物成分及颗粒大小进行了表征。结果表明:所制备的粉体在1 000℃煅烧2 h,粉体结晶良好,呈立方相结构,粉体颗粒在250 nm左右;采用同样的合成方法制备了掺杂的钛酸钡样品Ba0.9575Nd0.0025Ca0.04Ti0.815Mn0.0025Y0.0025Zr0.18O3,室温下XRD图表明,掺杂粉体呈立方相结构,这说明居里点调节到室温以下。由正温度系数LCR测量经1 200/1 300~1 350℃烧结的样品介电-温度谱图表明,介电常数(ε)随温度先增大后降低,在25℃附近获得最佳介电性能(εmax=15 775)。

Nano-sized Ba Ti O3(BTO)powders were prepared by the coprecipitation method.The phase analysis and particle size of the samples were characterized by X-Ray diffraction patterns(XRD)and scanning electron microscope(SEM).The results showed that high purity Ba Ti O3 powders with good crystallinity and with particle size of around 250 nm were obtained when the precursors was calcined at 1000℃for 2 h.Besides,doped BTO sample,Ba0.9575 Nd0.0025 Ca0.04 Ti0.815 Mn0.0025 Y0.0025 Zr0.18 O3,were also prepared by using the same method.The phase structure and dielectric properties of the doped Ba Ti O3 powders were determined by XRD and LCR.The XRD pattern at room temperature shows that the doping powder has cubic phase structure,indicating its Curie point was adjusted to below room temperature.The temperature dependence of the dielectric constant(ε)indicates thatεof doped BTO after sintering at 1200/1300~1350℃increases first,and then decreases instead with further increasing temperature.Thus,optimum dielectric property was obtained at about 25℃(εmax=15775).