2003/01/31 by S. V. Karpov, A. L. Bas'ko, A. K. Popov +2
Physics and Astronomy · #physics.optics #physics.atm-clus
published as Chapter in Resent Research Developments in Optics, vol. 2, Research Signpost, Trivandrum, India, 2002, pp. 427-463 · 37 pages, 18 figures, LaTeX2e with packages natbib, graphics
arxiv created 2003/01/31 · arxiv updated 2009/12/01
Based on the theory of the optical properties of fractal clusters, which is an operator-based modification of the coupled-dipole method, an alternate solution is proposed for the problem of adequately describing the evolution of optical spectra of any polydisperse silver colloid with particles falling within the range of most characteristic sizes (5 - 30 nm). This is the range over which the results of the application of the well-known methods of classical electrodynamics, including the Mie theory, disagree with experimental data. The effect of variation of the parameters of such media on optical spectra is studied by a numerical simulation, which accounts for particle electrodynamic dipole-dipole interactions. Indeed, such interactions are shown to be a key factor in determining the broadening of the sol absorption spectra during the course of fractal aggregation. A quantitative explanation is given for the reasons for the appearance of individual specific features in the contours of the spectral absorption of different types of silver colloids.