Light Extinction by Silver and Gold Colloidal Particles

Abstract

With the help of electron microscopy, digital processing of images and u.v. -visible spectrophotometry, the relationship between the maximum in the light extinction spectrum of colloidal particles of silver and gold (in a medium with refraction coefficient n ²⁰ _D = 1·5) and the maximum in their size distribution was studied. Sizes of particles and maxima in their extinction spectra are in the range of 0·3–0·35 nm, 430–830 nm (Ag) and 0·2–0·25 nm, 540–830 nm (Au) respectively. An analysis of the differences between theoretical and experimental dependence is also given.