We have employed the first-principles approach to compute the effective response of composites of graded spherical particles of arbitrary conductivity profiles. We solve the boundary-value problem for the polarizability of the graded particles and obtain the dipole moment as well as the multipole moments. We provide a rigorous proof of an ad hoc approximate method based on the differential effective multipole moment approximation (DEMMA) in which the differential effective dipole approximation (DEDA) is a special case. The method will be applied to an exactly solvable graded profile. We show that DEDA and DEMMA are indeed exact for graded spherical particles. © 2005 Elsevier B.V. All rights reserved.
Yu, K. W., & Gu, G. Q. (2005). Effective conductivity of composites of graded spherical particles. Physics Letters, Section A: General, Atomic and Solid State Physics, 345(4–6), 448–452. https://doi.org/10.1016/j.physleta.2005.07.037