Experimental Characterization of Clusters

William Weltner博士得到了实验物理化学项目的资助，研究了低温惰性气体基质中金属、半导体、碳和硅的小簇的物理性质。这些研究中使用的主要实验技术包括光谱学和ESR/ENDOR光谱学。由自旋多重度、对称性、光学跃迁、振动频率、g张量元素、超细分裂、零场参数和交换耦合常数组成的大量实验数据将用于表征以下类型的低温矩阵孤立团簇：1)过渡金属和稀土金属、中性金属和离子簇；2)碳、硅、碳化硅、中性和离子团簇；无机反铁磁性和铁磁性晶体的离子团簇，如二氟化锰；4)贵金属微粒；5)小金属团簇与氧、氢、一氧化碳的反应产物。提出了一个广泛的ESR和振动光谱学计划，以允许观察具有大零场分裂的过渡金属团簇。

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.