Optical absorption spectra of matrix isolated silver atoms and their dependence on matrix properties

Abstract

The isolation of silver atoms in rare gas matrices has been studied as a function of the condensation parameters, such as condensation temperature, gas flow rate and dilution ratio, and of the matrix temperature. This was done to establish defined experimental conditions, which allow a comparison between the spectra of isolated species in various gas matrices. The isolation of silver atoms is increasingly favoured by decreasing condensation temperature, increasing gas : metal ratio and within the series from Ne to Xe. The tendency of the Ag atoms to become trapped at various sites increases with these trends resulting in broad and only partially resolved spectra. Owing to the substantial change in matrix structure with the condensation temperature T_K, the form of the spectra depends strongly on T_K. Annealing of these layers at temperatures up to 0.4 of the matrix triple point temperature results in well resolved atomic spectra indicating that most of the various sites are unstable at higher temperatures. The conditions are also given, at which metal aggregation is favoured.