Optical properties of a suspension of metal spheres

The Mie theory is used to find the in situ electric dipole polarizability of a sphere of arbitrary size and material. This size-dependent polarizability, together with the Clausius-Mossotti equation, yields an effective dipole generalization of the Maxwell Garnett equation for spheres of nonzero size. Calculated effective optical constants are used to find the reflectance from a suspension of Ag spheres. The results are in good agreement with the recent reflectance measurements of Lee et al. [Phys. Rev. B 37, 2918 (1988)] on porous glass media containing Ag particles.