高性能钛酸钡基无铅压电陶瓷的相结构调控及性能增强机理

发布时间：2018-03-22 18:03

  本文选题：钛酸钡　切入点：无铅压电陶瓷　出处：《北京科技大学》2015年博士论文　论文类型：学位论文

【摘要】：BaTiO3陶瓷是一种重要的功能材料。近年来,由于其压电性能取得了重大突破(d33=620pC/N),受到研究者们的广泛关注。然而,目前围绕高性能BaTiO3体系的研究仍然处于起步阶段。通过优化取代元素种类以及取代量,有望拓宽BaTiO3基无铅压电陶瓷的成分体系,获得多种高性能的新型BaTiO3基无铅压电陶瓷。本文拟通过组元优化以及相结构调控的方法,制备高性能BaTiO3基无铅压电陶瓷,深入研究组元含量的变化与陶瓷样品的相结构和电学性能的关联,并揭示性能的增强机理。 研究了Ca含量对(Ba,Ca)TiO3-0.04LiF基陶瓷相结构和电学性能的影响。随着Ca含量的增加,陶瓷样品的相结构由正交(O)相转变成赝立方(PC)相,且在Ca含量为0.02时,陶瓷样品具有O和PC两相共存,并获得了优异的电学性能d33=361pC/N和kp=0.412。 系统研究了(Ba,Ca)(Ti,Sn)O3基无铅压电陶瓷中各组元含量的变化对其相结构和电学性能的影响。通过调节各组元的相对比例,调控陶瓷样品的相结构,明晰了该体系的两相或多相共存成分区域,并分析两相或多相共存的相结构对陶瓷样品的压电、铁电和介电性能及电致应变的影响,揭示其性能增强机理。归纳出(Ba,Ca)(Ti,Sn)O3多元体系中关键区域的相图,并揭示了各组元含量的变化与相结构和电学性能的关联。研究发现：(Ba0.95Ca0.05)(Ti1-xSnx)O3陶瓷样品在χ=0.11时取得了高的压电性能d33=670pC/N,且在较宽的组分区域0.07≤x≤0.11内压电性能d33_500pC/N。此外,在BaTiO3-x(0.4CariO3-0.6BaSnO3)体系中,陶瓷样品取得了高的电致应变0.07%和逆压电系数d33*＝1444pm/V。研究结果表明：(Ba,Ca)(Ti,Sn)O3陶瓷是一种有前景的无铅压电陶瓷体系。 系统研究了高居里温度(0.7-x)BiFeO3-0.3BaTiO3-xBi(Mg1/2Ti1/2)O3体系中各组元含量的变化对其相结构和电学性能的影响。通过调节各组元的相对含量,调控陶瓷样品的相结构,使陶瓷样品在室温下具有R-PC两相共存,从而有效地增强其压电性能。研究发现：由于R-PC两相共存,陶瓷样品在χ=0.04时取得高的压电活性d33=154pC/N和居里温度TC=482℃,该结果表明BiFeO3-BaTiO3-Bi(Mg1/2Ti1/2)O3体系在高温压电装置领域具有良好的应用前景。
[Abstract]:BaTiO3 ceramics are one of the important functional materials. In recent years, the piezoelectric properties of BaTiO3 ceramics have made a great breakthrough, which has attracted wide attention of researchers. At present, the research on high performance BaTiO3 system is still in its infancy. By optimizing the type and quantity of substituted elements, it is expected to broaden the composition system of lead-free piezoelectric ceramics based on BaTiO3. A variety of novel lead-free piezoelectric ceramics based on BaTiO3 with high performance were obtained. In this paper, BaTiO3 based lead-free piezoelectric ceramics with high performance were prepared by means of component optimization and phase structure control. The relationship between the change of element content and the phase structure and electrical properties of ceramic samples was studied, and the enhancement mechanism of the properties was revealed. The effect of Ca content on the phase structure and electrical properties of Baancao TiO3-0.04LiF-based ceramics was studied. With the increase of Ca content, the phase structure of the ceramics changed from orthogonal phase to pseudo-cubic PC-phase, and when the Ca content was 0.02, the phase structure of the ceramics changed from the orthogonal phase to the pseudo-cubic phase. The ceramic samples have two phases, O and PC, and the excellent electrical properties of d33=361pC/N and KPA 0.412 have been obtained. The effect of the content of each component on the phase structure and electrical properties of the lead-free piezoelectric ceramics based on Bajiangcao TiZO 3 was systematically studied. The phase structure of the ceramic samples was regulated by adjusting the relative proportion of the components. The region of the two-phase or multi-phase coexisting components of the system is clarified, and the effect of the two-or multi-phase coexisting phase structure on the piezoelectric, ferroelectric and dielectric properties and the electrically induced strain of the ceramic sample is analyzed. The mechanism of performance enhancement is revealed, and the phase diagrams of the key regions in the multicomponent system are summarized. The relationship between phase structure and electrical properties was also revealed. It was found that the high piezoelectric properties of Ti _ (1-x) Sn _ (x) O _ (3) ceramic samples were obtained at 蠂 ~ (0.11), and the piezoelectric properties d _ 33500 PC _ (r / N) were obtained in a wide component region of 0.07 鈮，

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