Grenzflächen-Analyse durch Mie-Plasmon-Spektroskopie an Edelmetallclustern
type: CreativeWork
description: The topological and electronic structure of condensed matter in the nanometer range between molecule and solid state is an important topic of present fundamental research. Both size and interface phenomena and in particular the rise of interband transitions were determined in clusters on the nanometer scale with optical spectroscopy. Clusters made of silver are especially sensitive to these effects since they expose a very distinct Mie-resonance-absorption. Silver- and gold-cluster with the size of 2R = 2nm...4 nm were produced inside a thermal heater in a special high-vacuum-chamber by supersonic expansion. The cluster-density is high enough for an optical measurement in the free beam. Silver-clusters in the free beam can be compared with cluster of the same run deposited on different substrates or compared with clusters codeposited with various matrix-materials. For substrate coating and embedding matrix different materials were used: Oxides (Al2O3, Sb2O5, TiO2, SrTiO2, Cr2O3, SnO2, In2O3, ITO, SiO2), Fluorides (MgF2, CaF2, LiF), C60 and Si. The detected resonance-absorption cannot be described quantitatively within the classical Mie-Theory. The extended Mie-Theory allowed the identification of electron transfer between cluster and matrix and the interface-induced damping of the free electrons within the cluster. The width of the Mie-resonance absorption is caused mainly by the damping of the 5s-electrons in the silver-cluster. The damping depends on the cluster-size and on the chemical-interface damping at the cluster-matrix-interface. In this thesis the changes of interband-transitions in clusters compared to bulk silver were discovered by means of a Kramers-Kronig-Analysis. Electron-spill-out into the surrounding matrix, static charge transfer through chemical cluster-matrix-bonding and/or changed interband-transitions caused a shift between calculated and measured Mie-resonance maximum. The two-stage ellipsoidal model after the theory of Gans and Yamagushi tak…
abstract: The topological and electronic structure of condensed matter in the nanometer range between molecule and solid state is an important topic of present fundamental research. Both size and interface phenomena and in particular the rise of interband transitions were determined in clusters on the nanometer scale with optical spectroscopy. Clusters made of silver are especially sensitive to these effects since they expose a very distinct Mie-resonance-absorption. Silver- and gold-cluster with the size of 2R = 2nm...4 nm were produced inside a thermal heater in a special high-vacuum-chamber by supersonic expansion. The cluster-density is high enough for an optical measurement in the free beam. Silver-clusters in the free beam can be compared with cluster of the same run deposited on different substrates or compared with clusters codeposited with various matrix-materials. For substrate coating and embedding matrix different materials were used: Oxides (Al2O3, Sb2O5, TiO2, SrTiO2, Cr2O3, SnO2, In2O3, ITO, SiO2), Fluorides (MgF2, CaF2, LiF), C60 and Si. The detected resonance-absorption cannot be described quantitatively within the classical Mie-Theory. The extended Mie-Theory allowed the identification of electron transfer between cluster and matrix and the interface-induced damping of the free electrons within the cluster. The width of the Mie-resonance absorption is caused mainly by the damping of the 5s-electrons in the silver-cluster. The damping depends on the cluster-size and on the chemical-interface damping at the cluster-matrix-interface. In this thesis the changes of interband-transitions in clusters compared to bulk silver were discovered by means of a Kramers-Kronig-Analysis. Electron-spill-out into the surrounding matrix, static charge transfer through chemical cluster-matrix-bonding and/or changed interband-transitions caused a shift between calculated and measured Mie-resonance maximum. The two-stage ellipsoidal model after the theory of Gans and Yamagushi tak…
author: Hilger, Almuth
language: ger
keywords: info:eu-repo/classification/ddc/530, Metallcluster, Silber, Gold, Oberflächenplasmon, Optische Spektroskopie, Physik, Cluster
date published: 2003
date modified: 2026-07-30T19:42:31Z
provider: RWTH Aachen University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Publikationsserver der RWTH Aachen University