双稀土掺杂BCST陶瓷的研制及其性能结构的研究

采用溶胶—凝胶法合成了BCST（Ba0.62 Ca0.08 Sr0.3 TiO3）粉体,再经过二次固相掺杂稀土Pr6O11和Nd2O3获得BCST∶0.001Pr6 O11.xNd2 O3系列纳米粉体及陶瓷;采用XRD和SEM,等对粉体的相组成和陶瓷的微观形貌进行了表征,并用介电频谱仪测试了陶瓷的介电性能.结果表明：所得BCST∶0.001Pr6O11.0.002Nd2O3粉体主要为四方相纳米粉体;随着稀土Nd2O3掺杂量的增加,所获得的陶瓷的晶粒先逐渐变小随后又逐渐增大;当钕的掺杂量x=0.002时,所获得陶瓷的室温介电常数最高,而介电损失最小;各试样的介电常数随烧结温度的升高增大,在1 330℃,1 360℃和1 400℃温度下烧结所获得的S1-陶瓷,介电常数的峰值εmax分别为10 360、12 490、13 750;其居里温度显著降低（10℃）,介温曲线呈单峰,介电常数随温度的变化敏感而对称,有望在温度敏感陶瓷方面发现其应用.

Preparation and Structure and Dielectric properties of BCST Doped with Pr and Nd

Sol-gel method was used to synthesize BCST(Ba0.62Ca0.08Sr0.3TiO3) powder.And then nanometer-sized BCST∶0.001Pr6O11·xNd2O3 series powders and ceramics were prepared by dopingPr6O11 andNd2O3 through solid state doping method.The phases of the powders were tested by X-ray Diffraction,the patterns of the1 ceramics were observed by SEM,and the dielectric properties were measured by Dielectric Frequency and Temperature Spectrum Analyzer.The results showed that the BCST∶0.00Pr6O11·0.002Nd2O3 powder was found to be tetragonal phase and nanometer-size;with the increase of the doping quantity ofNd2O3 the grain size of the BCST∶0.001Pr6O11·xNd2O3 series ceramics became smaller and then larger gradually;the ceramic had the highest dielectric constant and the lowest dielectric loss at room temperature when x=0.002;the dielectric constant of each ceramic sample became higher with the increase of the sinter temperature.