BCZT陶瓷的Nd^(3+)掺杂机制与介电性能研究

Nd^(3+) Doping Machanism and Dielectric Properties of BCZT Ceramics

采用固相合成法制备了(Ba_(0.92-x)Ca_(0.08)Nd_x)(Ti_(0.82)Zr_(0.18))O_3(0≤x≤0.02)陶瓷样品,借助XRD、LCR等手段对该陶瓷的结构和介电性能进行了研究。结果表明:当x=0.015时,陶瓷样品出现第二相。通过GULP软件模拟计算并结合实验数据分析可知:随着Nd^(3+)浓度增加,Ti^(4+)空位补偿机制优先发生,可能伴有少量自我补偿。增大Nd^(3+)掺杂量,介电常数与介电损耗均呈现下降趋势,介电峰值扩展并向低温移动。随着Nd^(3+)掺杂量增加,陶瓷样品呈现弛豫型铁电体特征,这与偏离平衡位置Nd^(3+)和缺陷偶极子[4Nd_(Ba)~·+V_(Ti)~″″]产生的无规场有关。

（Ba 0.92- x Ca 0.08 Nd x ）（Ti 0.82 Zr 0.18 ）O 3 （0≤ x ≤0.02）ceramics samples were prepared based on solid-state reaction methods. XRD, LCR and other techniques were utilized to investigated the microstructure and dielectric properties of the samples. The results show that when the doping amount is 0.015, the second phase occurs. Associated with the experiment date, the analysis indicates that with the increasing Nd 3＋ concentration, the Ti 4＋ vacancies compensation mechanism occurred preferentially by the general utility lattice program （GULP）, maybe accompanied by a small amount of self-compensation. With Nd 3＋ content increasing, both dielectric constant and dielectric loss decline, and the dielectric peak temperature shiftes to low temperature and the dielectric peak is broaden. With the increasing Nd 3＋ content, the dielectric relaxation characteristics are obtained. This is attributed to the random field induced by off-center Nd 3＋ ions and defect dipoles [4Nd Ba ＋V ″″ Ti ].