Jamnik J, Kalnin J R, Kotomin E A, Maier J
National Institute of Chemistry, Hajdrihova 19, SI-1000, Ljubljana, Slovenia.
Phys Chem Chem Phys. 2006 Mar 21;8(11):1310-4. doi: 10.1039/b514448p. Epub 2006 Feb 15.
In this paper we discuss the implementation of different equilibrium concentrations in each of the phases into the Maxwell-Garnett effective medium formula for diffusion in heterogeneous media. We put the derivation given by Kalnin et al., J. Phys. Chem. Solids, 2002, 63, 449, on safer grounds and extend it to non-dilute carrier concentrations. The relation to Maxwell's mixing rule is also elaborated. It is shown that the formula can not only successfully be applied to conductivity problems but also to describe steady state chemical diffusion in heterogeneous media such as polycrystalline samples. The comparison with the brick layer model corroborates these points but also shows that-in the case of heterogeneous media-one has to be cautious in applying steady state results to transient kinetics.
在本文中，我们讨论了如何将各相中不同的平衡浓度纳入麦克斯韦-加尼特有效介质公式，以用于非均匀介质中的扩散。我们使卡尔宁等人在《固体物理化学杂志》2002年第63卷第449页给出的推导更加可靠，并将其扩展到非稀释载流子浓度情况。还阐述了与麦克斯韦混合规则的关系。结果表明，该公式不仅能成功应用于电导率问题，还能描述多晶样品等非均匀介质中的稳态化学扩散。与砖层模型的比较证实了这些观点，但也表明，在非均匀介质的情况下，将稳态结果应用于瞬态动力学时必须谨慎。
