The effect of inhomogeneities in particle distribution on the dielectric properties of composite films

A practical approach for the modelling of the dielectric constants of thin composite films is presented. A general distribution function for composition fluctuations in the thin composite films is introduced to describe the transition from a non-percolative to a percolative morphology using physically meaningful parameters and is applied to model a wide range of experimental and simulated polymer–ceramic composite film behaviour from the literature, up to ceramic particle filler volume fractions of 75%. The parameters describing the morphologies of the various composites are used to predict effective dielectric properties with good accuracy. The model is applied further to composites that show early percolation behaviour, and the deviation of their effective dielectric behaviour from the standard effective medium theory at high filler volume fractions is discussed.

[1]  J. Cavaillé,et al.  Anomalous percolation transition in carbon black-epoxy composite materials , 1999 .

[2]  Christian Brosseau,et al.  Finite-element method for calculation of the effective permittivity of random inhomogeneous media. , 2005, Physical review. E, Statistical, nonlinear, and soft matter physics.

[3]  S. Kaptanoglu.  Nonleptonic charmed-meson decays , 1978 .

[4]  R. Whatmore,et al.  Structure modification of 0–3 piezoelectric ceramic/polymer composites through dielectrophoresis , 2005 .

[5]  D. McLachlan,et al.  An equation for the conductivity of binary mixtures with anisotropic grain structures , 1987 .

[6]  Lagarkov An,et al.  Electromagnetic properties of composites containing elongated conducting inclusions , 1996 .

[7]  William M. Merrill,et al.  Analytic framework for the modeling of effective media , 1998 .

[8]  Abderrahmane Beroual,et al.  Computational electromagnetics and the rational design of new dielectric heterostructures , 2003 .

[9]  D. A. G. Bruggeman.  Berechnung verschiedener physikalischer Konstanten von heterogenen Substanzen. I. Dielektrizitätskonstanten und Leitfähigkeiten der Mischkörper aus isotropen Substanzen , 1935 .

[10]  I. Jacobs,et al.  The influence of particle shape on dielectric enhancement in metal-insulator composites , 1992 .

[11]  H. Fricke,et al.  A Mathematical Treatment of the Electric Conductivity and Capacity of Disperse Systems I. The Electric Conductivity of a Suspension of Homogeneous Spheroids , 1924 .

[12]  Doyle,et al.  Effective cluster model of dielectric enhancement in metal-insulator composites. , 1990, Physical review. B, Condensed matter.

[13]  David Stroud,et al.  Percolation effects and sum rules in the optical properties of composities , 1979 .

[14]  Yang Rao,et al.  A precise numerical prediction of effective dielectric constant for polymer-ceramic composite based on effective-medium theory , 2000 .

[15]  O. Hunderi,et al.  Optical properties of Ag-SiO 2 Cermet films: A comparison of effective-medium theories , 1978 .

[16]  S. Shtrikman,et al.  A Variational Approach to the Theory of the Effective Magnetic Permeability of Multiphase Materials , 1962 .

[17]  O. Hunderi,et al.  Conductivity of inhomogeneous materials: Effective-medium theory with dipole-dipole interaction , 1978 .

[18]  G. Batchelor,et al.  Transport Properties of Two-Phase Materials with Random Structure , 1974 .

[19]  Haisheng Xu,et al.  High-dielectric-constant ceramic-powder polymer composites , 2000 .

[20]  Takeshi Yamada,et al.  Piezoelectricity of a high‐content lead zirconate titanate/polymer composite , 1982 .