南京大学学报(自然科学版) ›› 2016, Vol. 52 ›› Issue (5): 802–.

• • 上一篇    下一篇

不连续金属膜的介电性能计算

顾利民,王 强,杨 燚*,唐东明,张豹山   

  • 出版日期:2016-09-25 发布日期:2016-09-25
  • 作者简介:南京大学电子科学与工程学院,南京,210023
  • 基金资助:
    基金项目:国家自然科学基金(11004095,61271077,11104134) 收稿日期:2016-04-22 *通讯联系人,E­mail:malab@nju.edu.cn

Calculations of dielectric properties of discontinuous metal films

Gu Limin,Wang Qiang,Yang Yi*,Tang Dongming,Zhang Baoshan   

  • Online:2016-09-25 Published:2016-09-25
  • About author: School of Electronic Science and Engineering,Nanjing University,Nanjing,210023,China

摘要: 采用Bruggeman有效媒质理论、基于HFSS软件的S参数法和谐振腔微扰法对不连续金属膜的介电常数进行计算.计算结果表明,在满足长波准静态近似条件下,通过对金属的介电常数进行重整化处理,将涡流效应和局域场增强效应纳入到重整化介电常数中,可以将金属等效为均匀极化的介质,并利用有效媒质理论解析的计算出不连续金属膜的介电常数.且在不连续金属膜中,由于涡流效应的影响,不连续金属膜单元尺寸的大小将显著影响到不连续金属膜的有效介电常数.另外,Bruggeman理论在计算填充浓度小于阈值的样品时才可以获得准确结果.该文结论对研究不连续金属膜的介电性质具有积极的指导意义.

Abstract: In the paper,the complex permittivity of discontinuous films was calculated using Bruggeman effective medium theory(EMT),moreover,an S parameter retrieved method based on HFSS software and a cavity perturbation method were also used for comparison to verify the EMT results.The calculation results indicate that the effective permittivity of discontinuous films can be analytically calculated using Bruggeman effective medium theory when the condition of long wave approximation is met,which gives a convenient routine to get the permittivity of discontinuous films.The metal permittivity based on Drude equation has been renormalized to be used in Bruggeman theory,and the renormalized metal permittivity effectively reflects the influence of eddy effect and enhanced effect of local electric field,so that the metal unit can be considered as a homogenously polarized medium in the discontinuous films.Due to eddy effect,the size of metal unit would remarkably influence the effective permittivity of discontinuous films,which means that the larger unit size will result in the higher renormalized metal permittivity.The effective permittivity could be tuned by controlling the metal unit size in the discontinuous metal films.Additionally,another key result is that the Bruggeman theory is effective only when the metal unit concentration is below the percolation threshold,because the effective medium theory is based on the assumption that the fields are the same in all metal units,which is the base to renormalize metal permittivity.This assumption does not hold when a metal concentration approaches the percolation threshold because the multipole scattering will take effect.All the results concluded in the paper give a rule to use EMT to handle the discontinuous metal films,and are very valuable in studying their dielectric properties.

[1] Yang Y,Zhang B S,Xu W D,et al.Microwave absorption studies of W­hexaferrite prepared by co­precipitation/mechanical milling.Journal of Magnetism and Magnetic Materials,2006,265:119-122. [2] Yang Y,Zhang B S,Xu W D,et al.Preparation and properties of a novel iron­coated carbon fiber.Journal of Magnetism and Magnetic Materials,2003,256:129-132. [3] Yang Y,Zhang B S,Xu W D,et al.Preparation and electromagnetic characteristics of a novel iron­coated carbon fiber.Journal of Alloys and Compounds,2004,365:300-302. [4] Zhao H,Xu S Y,Tang D M,et al.Thin magnetic coating for low­frequency broadband microwave absorption.Journal of Applied Physics,2015,116:243911_1-243911_4. [5] Yang Y,Liu B L,Tang D M,et al.Influence of the magnetic field annealing on the extrinsicdampingof FeCoB soft magnetic films.Journal of Applied Physics,2010,108(7):73902_1-073902_4. [6] Liu B L,Yang Y,Tang D M,et al.Research on double resonance peaks and abnormal frequency shift inpermeability spectra of annealed FeCoB films.Journal of Magnetism and Magnetic Materials.2011,323(3-4):375-378. [7] 黄学勤.等离子人工电磁材料的物性研究及其应用.博士学位论文.上海:复旦大学物理系,2009.(Huang X J.Research on properties and application of plasmonic metamaterials.Ph.D.Dissertation.Shanghai:Fudan University,2009.) [8] Zhou W J,Mandia D J,Griffiths M B E,et al.Effective permittivity of ultrathin chemical vapor deposited gold films on optical fibers at infrared wavelengths.Journal of Physical Chemistry C,2014,118(1):670-678. [9] 邝向军.关于金属介电常数的讨论.四川理工学院学报(自然科学版),2006,19(2):75-78.(Kuang X J.Discussion on dielectric constant of metal.Journal of Sichuan University of Science Egineering(Natural Science Edition),2006,19(2):75-78.) [10] 曹晓晖,黄荣芳,闻立时等.微粒子复合体介电特性有效媒质理论的形状修正.复合材料学报,1996,13(1):60-65.(Cao X H,Huang R F,Wen L S,et al.Shape modification of for the effective medium theory of the dielectric property of small particle composite.ACTA Materiae Compositae Sinica,1996,13(1):60-65.) [11] Andrey K S,Mcphedran R C,Vladimir M S.Electrodynamics of metal­dielectric composites and electromagnetic crystals.Physical Review B,2000,62(12):8531-8539. [12] 景莘慧,蒋全兴.基于同轴线的传输/ 反射法测量射频材料的电磁参数.宇航学报,2005,26(5):630-634.(Jing S H,Jiang Q X.Transmission reflection method based on coaxialLine for RF materials characterization measurement.Journal of Astronautics,2005,26(5):630-634.) [13] 陶 洁.磁性纳米膜微波电磁参量谐振腔法测量研究.硕士学位论文.武汉:华中科技大学,2006.(Tao J.Investigation of measurement for microwave electromagnetic parameters of nanostructural magnetic Thin films by cavity perturbation method.Master Dissertation.Wuhan:Huazhong University of Science & Tech­nology,2006.) [14] 王振林.表面等离激元研究新进展.物理学进展,2009,29(3):287-324.(Wang Z L.A review on research progress in surface plasmons.Progress on Physics,2009,29(3):287-324.) [15] Slovick B A,Yu Z G,Krishnamurthy S.Generalized effective­medium theory for metamaterials.Physical Review B,2014,89(15):155118_1-155118_5. [16] Hovel M,Gompf B,Dressel M.Dielectric properties of ultrathin metal films around the percolation threshold.Physical Review B,2010,81(3):035402_1-035402_8.
No related articles found!
Viewed
Full text


Abstract

Cited

  Shared   
  Discussed   
No Suggested Reading articles found!