【作者】 郝利军；

【导师】 许启明；

【作者基本信息】 西安建筑科技大学 ， 材料物理与化学， 2009， 硕士

【摘要】 随着移动通讯和计算机技术的迅猛发展,叠层片式电感作为一类重要的电子元器件,得到了广泛应用和深入研究。铋钙钒系列石榴石铁氧体有着良好的磁性能和烧结特性,且成本更低,成为低温烧结石榴石铁氧体的最佳选择。本文围绕低温烧结Bi-CVG铁氧体的电磁特性以及掺杂对其的影响进行了较为系统的研究。本文以Y₂O₃、Fe₂O₃、Bi₂O₃、V₂O₅、CaCO₃、In₂O₃和B₂O₃为原料,采用传统的陶瓷工艺制备了Bi-CVG系列铁氧体材料。首先探讨烧结工艺条件对改善主配方Bi-CVG铁氧体微观结构和磁性能的作用;其次研究了掺杂、烧结温度等因素对Bi-CVG系列铁氧体性能的影响规律和作用机制。通过X射线衍射仪分析（XRD）、扫描电子显微技术（SEM）、软磁材料自动测试系统（MATS）、射频阻抗/材料分析仪等方法考察了不同烧结温度、保温时间对产物体积密度、晶体结构、形貌、磁性能和介电性能的影响。结果表明:（1）选择适当的预烧温度（900℃）可以有效提高Bi-CVG铁氧体的密度;烧结温度对相稳定性和电磁性能影响显著,而保温时间对其影响相对较小。当烧结条件为1100℃×6h时,所制备的Bi-CVG样品性能良好,平均晶粒尺寸约2μm,密度为5.20g/cm³;主要性能为Br=24.57mT,Hc=764.4A/m,4πMs=343.2×10^-4T,tanδ_ε=4.34×10^-4,ε=13.92。（2）In取代可以改善Bi-CVG铁氧体的磁性能和介电性能。适量的In取代使样品的相对密度、饱和磁化强度Ms、剩磁Br和电阻率ρ增大;而矫顽力Hc、介电损耗tanδ_ε和介电常数ε均降低;同时In取代促进了Bi-CVG铁氧体的晶化,使烧结温度有所降低。本实验发现In的最佳取代量在x=0.4～0.6范围内。（3）掺B可以有效降低Bi-CVG铁氧体的烧成温度。随着B掺杂量的增多,Bi-CVG铁氧体的电阻率逐渐增大,介电损耗tanδ_ε、剩磁Br、和饱和磁化强度4πM_s和矫顽力Hc略有降低。在1060℃×6h条件下烧结B₂样品,其电磁特性较佳:室温时D=5.11g/cm³,D_R.T=97.2%,Bs=37.30mT,Br=25.54mT,Hc=0.87kA/m,ρ=3.67×10¹⁰Ω·cm,tanδ_ε=3.94×10^-4。本论文工作所研制的Bi-CVG系复合石榴石铁氧体材料,在维持电磁特性较佳的同时,烧结温度有了较大幅度的降低,完全满足同银钯（Ag-Pd:1145℃）电极共烧的要求,在低温烧结方面表现出独特的优势,因而具有良好的应用前景。更多还原

【Abstract】 With the development of telecommunications and computer technology,a kind important electronic components with multilayer chip inductors have been deeply researched and got extensive applications.The Bi-CVG ferrites have better magnetic and sintering properties and especially the lower cost,and are the best choice for low sintering YIG.For this reason,this dissertation presents a systematical study on the electrical and magnetic properties of the low temperature sintered Bi-CVG ferrites and the effect of additions on it.In this dissertation,we used Y₂O₃,Fe₂O₃,Bi₂O₃,V₂O₅,CaCO₃,In₂O₃ and B₂O₃ as the raw material.The Bi-CVG ferrites have been sinstered with lower temperature. It’s suggested that sintering conditions had the effect on microstructure and magnetic properties of Bi-CVG and did research the doping and sintering temperature on the laws and mechanisms of Bi-CVG series ferrite properties.In order to further researches on these influences,we also observed that the effect of different sintering temperature, soaking time and doped content of the bulk density,structure,morphology,magnetic and dielectric properties was investigated by XRD,SEM,MATS and RF impedance material analyzer.The results were outlined here with:（1） Appropriate pre-sintered temperature can effectively increase the density of ferrite,and the sintering temperature has significant effect on the stability of YIG phase and magnetic properties,but soaking time has relatively small influence on it.It is suggested that the as-prepared at 1100℃for 6h has a better properties.The average grain sizes of sample is about 2μm,ρ=5.20g/cm³,The main magnetic parameters are B_r=24.57 mT,H_c=764.4 A/m,4πM_s=343.2×10^-4T,tanδ_ε=4.34×10^-4,ε=13.92。 （2） In-substituted may improve magnetic and dielectric properties of Bi-CVG Ferrite material.This is accompanied by a significant increase in the relative density, saturation magnetization（4πMs）,remanent magnetization and resistivity,and a significant reduction in coercivity,dielectric loss of the appropriate In-substitution. In-substituted accelerated crystallization and lowered sintering temperature of Bi-CVG ferrites.We found that the most optimized content of In-substituted is 0.4～0.6.（3） B-substituted may significant reduced the sintering temperature of Bi-CVG ferrite material.With a significant increase in the B-doped content,resistivity increases, dielectric loss tanδ_ε,saturation magnetization（4πMs）,remanent magnetization and coercivity slight decrease.It is suggested that the as-sintered B₂ sample at 1060℃for 6h has a better electric-magnetic properties.The main electric-magnetic parameters are D=5.11g/cm³,D_R.T=97.2%,B_s=37.30mT,B_r=25.54mT,H_c=0.87kA/m,ρ=3.67×10¹⁰Ω·cm,tanδ_ε=3.94×10^-4。When keeping a high electromagnetic property,Bi-CVG composite garnet ferrites we study in this dissertation may significant lower sintering temperature.The R:Bi-CVG（R=In,B） materials can be co-fired with Ag-Pd-electrode materials and show good potential for low-temperature sintering.This kind of Bi-CVG ferrite has optimistic applying foreground.更多还原