纳米BaTiO3/BaFe12O19复合材料的铁电、磁介电及磁电耦合性能研究

With the development of electronic information technology, electronic components meet the trend of miniaturization and multi-functional. In this study, we focus on the preparation of (1-x)BaTiO3/xBaFe12O19 (0≤x≤0.5) nano-composite with uniform structure and phases. BaTiO3 and BaFe12O19 nano-powders synthesized by microwave hydrothermal methods are mixed by constructing a highly uniform ferromagnetic and ferroelectric system.A high-quality homogeneity ceramic composite material with less macroscopic defects, uniform phase and structure will be obtained by the microwave sintering technology in order to control two-phase grain size and inhibit the interface reaction and diffusion.The morphology evolution of nanoparticles by means of scanning electron microscopy, transmission electron microscopy, piezoresponse force microscope and magnetic force microscope were observed. In order to obtain the bifunctional material which has an appropriate dielectric loss in a certain frequency range, the influence of nano-structure and interface characteristics on the ferroelectric- ferromagnetic properties and microwave absorbing properties will be investigated by ferroelectric- dielectric , ferromagnetic and microwave absorbing measurements. Based on the results, it is possible to achieve the components integrated in low-dimensional and explain the magnetoelectric coupling property deterioration problems for the mismatch between two grain size, phase heterogeneity, the reaction between two phases and the decrease of electrical resistivity, the interface properties provide a theoretical basis for the design of new multiferroic materials.

电子信息技术的发展迫切需要各种电子元器件实现微型化和多功能化。本研究采用微波水热法合成BaTiO3和BaFe12O19纳米粉体，通过构建高度均匀的铁磁和铁电两相体系，利用微波烧结的快速致密化技术，达到控制两相晶粒尺寸，抑制界面互反应和扩散，减少材料宏观缺陷，最终获得物相、结构均匀的(1-x)BaTiO3/xBaFe12O19(0≤x≤0.5)纳米复合陶瓷材料。用扫描电镜、透射电镜、压电力显微镜、磁力显微镜等测试手段观察纳米颗粒的形貌演变过程，以铁电-介电性能测定、铁磁性能测定和微波吸收性能等检测为手段，研究复合材料的纳米结构、界面特性对材料铁电-磁介电及微波吸收性能的影响，旨在获得某一频段内适合损耗的双功能性材料。实现材料在低维尺度上的复合，解决由于颗粒尺寸不匹配、混合不均匀以及物相之间发生反应、电阻率降低而降低材料磁电耦合性能的问题，为设计新型多功能性多铁性材料提供理论依据。

电子信息技术的发展迫切需要各种电子元器件实现微型化和多功能化。 本研究采用微波水热法合成 BaTiO3 和 BaFe12O19 纳米粉体，通过构建高度均匀的铁磁和铁电两相体系，利用微波烧结的快速致密化技术，达到控制两相晶粒尺寸，抑制界面互反应和扩散，减少材料宏观缺陷，最终获得物相、结构均匀的(1-x)BaTiO3/ xBaFe12O19 (0≤x≤0.2)纳米复合陶瓷材料。利用扫描电镜、透射电镜等测试手段观察纳米颗粒的形貌演变过程，以铁电-介电性能测定、铁磁性能测试等检测为手段，研究不同复合结构（0-3型、3-0型以及2-2型复合结构）的BaTiO3-BaFe12O19复合材料的纳米结构、界面特性对材料铁电-磁介电性能的影响。解决复合材料中颗粒尺寸不匹配、混合不均匀、材料绝缘特性恶化等问题，为设计新型多功能的多铁性材料提供理论依据。所制备的2-2型0.8BaTiO3-0.2BaFe12O19复合陶瓷在1.8 T外磁场下其磁介电系数最大可达到6.71%，具有良好的应用前景。