LTCC磁介复合陶瓷的制备及电磁性能研究

【作者】 苏丽娜；

【导师】 刘鹏；

【作者基本信息】 陕西师范大学 ， 凝聚态物理， 2010， 硕士

【摘要】 复合电子材料由于其独特的物理和多功能特性而同时显示出磁和介电性能。最近,随着低温共烧陶瓷(LTCC)技术和集成芯片元素的发展,这种具有显著磁导率和介电常数的新型复合材料得到了广泛研究。由于其同时具有电感和电容的功能,这种材料可用来制作无源集成复数零件,比如滤波器,在减少印刷电路板的占用空间、并进一步促进无源集成零件的小型化方面具有显著优势,可见这一新型复合材料在将来的电子器件生产方面具有潜在的应用价值。但是,这种同时具有铁磁和介电性能的高品质复合材料的研究一直面临着巨大挑战。本论文中,在Bi2O3烧结助剂的帮助下,我们分别制备了xTiO2+(1-x)Ni0.2Cu0.2Zn0.620(Fe2O3)0.98(NiCuZn ferrite)(0≤x≤60wt.%)和xBa0.6Sr0.4TiO3(BST)+(1-x)Ni0.2Cu0.2Zn0.62O(Fe203)0.98(NiCuZn ferrite)(0≤x≤60wt.%)复合陶瓷。NiCuZn铁氧体由于其高磁导率、高居里温度、高频率性能佳和相对较小的损耗被选为铁磁相。中介电常数和低介电损耗的TiO2是一种众所周知的性能优越的介电材料,被选为介电相之一,(Ba,Sr)TiO3由于其高介电常数等一系列优点被选为介电基体材料之二。本论文研究了两种复合陶瓷的烧结行为、微观结构以及电磁性能。用标准的电子陶瓷工艺法首次制备了xTi02+(1-x)Ni0.2Cu0.2Zn0.62O(Fe2O3)0.98(NiCuZnferrite)(0≤x≤60wt.%)复合陶瓷。在3wt.%Bi2O3的帮助下,所有陶瓷样品均在900℃烧结成瓷。XRD结果显示陶瓷样品由NiCuZn、Fe3Ti3O10和TiO2三相组成。从SEM图谱可以看出,10wt.%Ti02-90wt.% Ni0.2Cu0.2Zn0.620(Fe2O3)0.98的陶瓷拥有较小的晶粒尺寸和较高的密度。随着Ti02含量的增加,相对介电常数εr先增大,在x=10wt.%处达到最大,然后减小。样品的磁导率和饱和磁化强度随TiO2含量的增加缓慢减小,其中磁导率显示出了优异的频率稳定性。含10wt.%TiO2的复合材料显示出了典型的磁滞回线。10wt.%Ti02-90wt.%Ni0.2Cu0.2Zn0.62O(Fe2O3)0.98这一陶瓷组分在900℃的低温下显示出了较好的介电和磁性能(εr=50,30,tanδμ=0.13)。同样,用固相反应法首次制备了xBa0.6Sr0.4TiO3(BST)+(1-x)Ni0.2Cu0.2Zn0.62O(Fe2O3)0.98(NiCuZn ferrite)(0≤x≤60wt.%)复合陶瓷。加入3wt.%Bi2O3后,所有复合陶瓷均在925℃时得到了>95%的相对密度。XRD结果显示复合陶瓷均由BST和NiCuZn铁氧体相组成。在NiCuZn铁氧体和BST之间发生了离子扩散,影响了陶瓷的电性能。随着BST含量的增加,复合陶瓷的介电常数增加,同时磁导率降低。40wt.%Ba0.6Sr0.4Ti03-60wt.%Ni0.2Cu0.2Zn0.620(Fe2O3)0.98这一陶瓷组分在950℃的低温下显示出了较好的介电和磁性能(εr=48,tanδ|ε=0.01,μ=20.8,tanδμ|10MHz=0.03),同时也表现出了优异的频率稳定性(fr=100MHz)。综上所述,10wt.%TiO2-90wt.Ni0.2Cu0.2Zn0.62O(Fe2O3)0.98和40wt.Ba0.6Sr0.4TiO3-60wt.Ni0.2Cu0.2Zn0.62O(Fe2O3)0.98两种复合陶瓷均显示出了优异的整体性能,可以被用作电感、电阻和电容。更多还原

【Abstract】 Composite electronic materials exhibit both magnetic and dielectric properties due to their unusual physics and multi-functions. Recently, with the development of low-temperature co-fired ceramics (LTCC) technology and integrated chip elements, such composite materials with significant permeability and permittivity were extensively researched. Because of their both inductive and capacitive functions, these composite materials can be used to manufacture truly integrated passive complex elements, such as filters, by a single material, which has obvious advantages in reducing the space occupied by printed circuit boards and further allowing the miniaturization of the integrated elements. So they have potential application in the production of electronic devices in future. However, development of a high-quality composite material with simultaneous ferromagnetic and ferroelectric characteristics is an ever challenging aspect for investigation. In this paper, we prepared the xTi02+(1-x)Ni0.2Cu0.2Zn0.620(Fe2O3)0.98 (NiCuZn ferrite) (0≤x≤60 wt.%) and the xBao.6Sro.4Ti03 (BST)+(1-x)Ni0.2Cu0.2Zn0.620(Fe2O3)0.98(NiCuZn ferrite) (0≤x≤60wt.%) composite ceramics respectively, with addition of Bi2O3 as a sintering agent. Here, NiCuZn ferrite is chosen as a ferrite phase because of its high permeability, high curie temperature, high frequency, and relative low loss tangent. TiO2 is a dielectric phase due to its high dielectric constant and relatively low dielectric loss. And (BaSr)TiO3 is a dielectric compound with a large figure of merit and superior dielectric properties. The sintering behaviors, phases, microstructures, and electromagnetic properties of studied systems were investigated.A series of xTi02+(1-x)Ni0.2Cu0.2Zn0.62O(Fe2O3)0.98 (NiCuZn ferrite) (0≤x≤60 wt.%) composite ceramics were primarily prepared by a solid-state reaction method. With addition of 3 wt.% Bi2O3, all the ceramics can be sintered at 900℃. The effects of composition x on the sintering behaviors, phase compositions and electromagnetic properties of TiO2+NiCuZn ferrite ceramics were investigated. X-ray diffraction (XRD) results showed that the ceramics were composed of NiCuZn, Fe3Ti3O10 and TiO2 phases. Scanning electron micrographs showed that 10 wt.% TiO2-90 wt.% Ni0.2Cu0.2Zn0.620(Fe2O3)0.98 ceramics had small grain size and high density. With an increase of TiO2 content x, the value ofεr decreased and the component with 10 wt.% TiO2 had maximum relative dielectric constant. The permeability and the saturation magnetization decreased gradually with increasing TiO2 content, and the permeability curve exhibited excellent stability of frequency. The composite materials with 10 wt.% TiO2 showed typical magnetic hysteresis of the magnetic materials. For the specimens with 10 wt.% TiO2-90 wt.%Ni0.2Cu0.2Zn0.620(Fe2O3)0.98, the good dielectric (εr=50) and magnetic properties (μ=30, tanδμ=0.13) have been obtained at 900℃.xBa0.6Sr0.4TiO3 (BST)+(1-x)Ni0.2Cu0.2Zn0.620(Fe2O3)0.98 (NiCuZn ferrite) (0≤x≤60 wt.%) composite ceramics were primarily prepared by a solid-state reaction method. With addition of 3 wt.% Bi2O3, all the composite ceramics can be sintered to a density>95% of theoretical density at 925℃. The effects of composition x on the sintering behaviors, phase compositions and electromagnetic properties of BST+NiCuZn ferrite composite materials were investigated. X-ray diffraction (XRD) results showed that the composites were composed of BST and NiCuZn phases. The ions diffusion was found to take place between NiCuZn ferrite and BST, which affected the electrical properties of the ceramics. With an increase of BST content x,the dielectric constant of the composites increases and the permeability decreases. For the specimens with 40 wt.% Bao.6Sro.4Ti03-60 wt.% Ni0.2Cu0.2Zn0.62O(FeO3)0.98, the good dielectric (εr=48,tanδ|ε=0.01)and magnetic properties (μ=20.8, tanδμ|10MHz=0.03) have been obtained at 950℃. Meanwhile, it exhibited excellent frequency stability which was up to fr=100 MHz.In conclusion, the 10 wt.% TiO2-90 wt.% Ni0.2Cu0.2Zn0.62O(Fe2O3)0.98 ceramic and the 40 wt.% Bao.6Sro.4Ti03-60 wt.% Ni0.2Cu0.2Zn0.62O(Fe2O3)0.98 composite exhibit excellent integrated properties, which can be used not only as inductors and resistors but also as capacitors.更多还原