Optical properties of a small-particle composite

Abstract

Room-temperature reflectance measurements over frequencies between the far infrared and the ultraviolet have been made on composites of silver small particles and potassium chloride grains. The optical properties of these composites were obtained by Kramers-Kronig analysis. Comparison of the data with the Maxwell-Garnett theory and the effective-medium approximation showed that the effective-medium approximation better described the data. A sum-rule analysis indicates that the expected linear relationship between the volume fraction of metal and the integrated oscillator strength is obeyed.