A位离子改性对BaBi4Ti4O15陶瓷电学性能的影响

Effect of A-Site Ion Modification on the Structure and Electrical Properties of BaBi4Ti4O15 Ceramics

为了探究Nd3+对BaBi4Ti4O15(BBT)陶瓷A位不同元素进行取代所造成的结构以及介电性能的影响,文中采用传统固相法制备了Ba1-xNdxBi4Ti4O15(BNBT,其中x=0.05,0.10)陶瓷和BaBi4-xNdxTi4O15(BBNT,其中x=0.05,0.10)陶瓷,采用X射线衍射分析仪(XRD)表征材料的相结构,利用HP4294A自动测试系统测试不同频率下的介电常数ε′和介电损耗tanδ随温度T(室温到500℃)的变化情况。通过修正的居里-外斯定律和洛伦兹经验公式,对Nd^3+取代BBT陶瓷的相变过程中产生的介电弛豫现象进行分析与表征。研究结果表明:通过A位改性可以有效改善BBT陶瓷的居里温度和弛豫程度,不同的Nd^3+掺杂量以及改性位置对BBT陶瓷结构和电学性能的影响不同,当Nd^3+取代BBT陶瓷的Ba^2+位时,随着掺杂量的增加,BBT陶瓷的弛豫程度和弥散强度逐渐增强;当Nd3+取代BBT陶瓷的Bi^3+位时,BBT陶瓷的弛豫程度逐渐减弱。

Ba1-xNdxBi4Ti4O15 (x =0.05,0.10) and BaBi 4-xNdxTi4O15 (x =0.05,0.10) ceramics were prepared by using the convention solid-state reaction method.Effect of neodymium substitution on the structural and dielectric properties of BaBi4Ti4O15 (BBT) ceramic was investigated.Phase structure was characterized by X-ray diffraction analysis (XRD).Dielectric permittivity and loss were measured at various temperatures (ranging from room temperature to 500 ℃) at different frequencies by using an HP4294A automatic system with a temperature-controlled chamber.The dielectric relaxation phenomenon in the phase transition of Nd^3+ substituted BBT ceramics was analyzed and characterized by the modified Curie-Weiss law and Lorentz empirical formula.The results show that the Curie temperature and relaxation degree of BBT ceramics can be effectively improved by A-site modification.Different Nd^3+ doping amount and modification position have different effects on the structure and electrical properties of BBT ceramics.When Nd^3+ doped Ba^2+ of BBT ceramics as the amount of doping increases,the relaxation degree and diffusion intensity of BBT ceramics increase gradually.When Nd^3+ doped the Bi^3+ position of BBT ceramics,the relaxation degree of BBT ceramics gradually decreases.