The effective dielectric function of composites consisting of particles dispersed in isotropic or anisotropic media is affected by the composition, size, shape, and orientation of the particles. Our first objective was to determine the effects of the particle’s shape and preferential orientation on the effective dielectric function of the medium. We have used the Maxwell Garnett effective medium approximation generalized for ellipsoidal particles in order to study the effective dielectric function of different Au nanoparticle systems, with both random and normal orientation of the ellipsoids in relation to the incident light, simulating the microstructure of many nanocomposite thin films grown by co-deposition or alternating deposition methods. Our second objective was to consider real particle systems by determining the effects of the particle shape distribution on the effective dielectric function. We have considered the Generalized Maxwell Garnett equations extended for systems of shape-distributed ellipsoids and have, for the first time, correlated the ellipsoid’s shape/aspect ratio with their geometrical factors in a single graphic. We have introduced and used 1D and 2D Gaussian shape probability distribution functions in order to calculate the effective dielectric function of a number of Au nanoparticle systems having different distributions of ellipsoidal shapes/aspect ratios. The multicomponent Generalized Maxwell Garnett approximation was also used in order to determine the effective dielectric function of Au nanoparticle systems containing mixtures of nanoparticles with different shapes and sizes.

中文翻译：

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形状分布椭球形粒子系统的介电性能

由分散在各向同性或各向异性介质中的颗粒组成的复合材料的有效介电功能受颗粒的组成，尺寸，形状和方向影响。我们的第一个目标是确定颗粒形状和优先取向对介质有效介电功能的影响。为了研究不同金纳米粒子系统的有效介电功能，其中椭球相对于入射光具有随机和法向取向，我们使用了麦克斯韦·加内特有效介质近似法对椭圆形颗粒进行了推广，以模拟许多纳米复合材料薄层的微观结构。通过共沉积或交替沉积方法生长的薄膜。我们的第二个目标是通过确定粒子形状分布对有效介电函数的影响来考虑真实粒子系统。我们考虑了扩展的形状分布椭球体系统的广义Maxwell Garnett方程，并且首次将椭球体的形状/长径比与它们的几何因子关联在单个图形中。为了计算许多具有不同椭圆形/长宽比分布的Au纳米粒子系统的有效介电函数，我们引入并使用了一维和二维高斯形状概率分布函数。