Dr. William Weltner is supported by a grant from The Experimental Physical Chemistry Program to investigate the physical properties of small clusters of metals, semiconductors, carbon and silicon which are trapped in low temperature inert gas matrices. The primary experimental techniques used in these studies include optical spectroscopy and ESR/ENDOR spectroscopy. A large body of experimental data consisting of spin multiplicities, symmetries, optical transitions, vibrational frequencies, g-tensor elements, hyperfine splittings, zero-field parameters, and exchange coupling constants will be used to characterize low temperature matrix isolated clusters of the follow types: 1) clusters of transition and rare-earth metals, neutrals and ions; 2) clusters of carbon, silicon, and silicon carbide, neutrals and ions; 3) ionic clusters of inorganic antiferrro- and ferro-magnetic crystals such as manganese difluoride; 4) microparticles of noble metals; and 5) reaction products of small metal clusters with oxygen, hydrogen and carbon monixide. An extensive program of ESR and vibrational spectroscopy in the far-infrared is proposed to allow the observation of transition metal clusters with large zero-field splittings.
