Niklasson G A, Granqvist C G, Hunderi O
Appl Opt. 1981 Jan 1;20(1):26-30. doi: 10.1364/AO.20.000026.
The Maxwell Garnett and Bruggeman effective medium theories are derived for the average dielectric permeability of heterogeneous materials from a unified theoretical approach. It starts by specifying two random unit cells which represent different microstructures. Requiring that these cells should not be detectable by electromagnetic radiation when embedded in an effective medium, we show from an extended optical theorem that the forward scattering amplitude must vanish. Setting the leading term in the expansion series of this quantity equal to zero yields the effective medium theories pertaining to the two microstructures. The remaining terms provide estimates of the accuracy of the approximations. This approach is then used in numerical computations for Co-AI(2)O(3) cermets.
麦克斯韦·加内特和布鲁格曼有效介质理论是从统一的理论方法推导出来的，用于计算非均匀材料的平均介电常数。该方法首先指定两个代表不同微观结构的随机单位晶胞。要求当这些晶胞嵌入有效介质中时，电磁辐射无法检测到它们，我们从扩展光学定理表明前向散射振幅必须为零。将该量展开级数中的首项设为零，得到了与这两种微观结构相关的有效介质理论。其余项提供了近似精度的估计。然后将这种方法用于钴 - 氧化铝金属陶瓷的数值计算。
