Optical response of concentrated colloids of coinage metals in the near-ultraviolet, visible, and infrared regions

The optical response of two-phase composite materials (cermet topography with coinage metals) at high filling factors under a wide range of particles sizes, frequencies, and experimental conditions is calculated using a model that combines multipolar interactions and particle size effects. The validity of the model is established for a real system of a silver colloid and the simulations are discussed in terms of the microscopic structural parameters and the interaction between the particles. The limitations of the Maxwell-Garnett model are explored and the transition between a dense system which primarily reflects light and a dilute composite which mostly transmits light is followed with the same model.