Optical properties of C60 molecules: A quasi-static approximation

In this paper, the optical properties of a C60 molecule is studied within the framework of the quasi-static approximation. To do this, a C60 molecule is modeled by an infinitesimally thin spherical shell of the π and σ electrons and electronic excitations of this shell is described by means of the two-dimensional two-fluid hydrodynamic theory. At the first, general expression for polarizability of the system is obtained, by solving Laplace and hydrodynamic equations with appropriate boundary conditions. Then, by using the polarizability formula, the extinction spectrum of system is investigated which is in quite agreement with the result of the Mie theory. Also, the Maxwell-Garnett theory for the effective medium approximation of composite materials is developed to study the dielectric response of a composite of C60 molecules.