Download or read book Optical Properties of Metal Clusters written by Uwe Kreibig and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical Properties of Metal Clusters deals with the electronic structure of metal clusters determined optically. Clusters - as state intermediate between molecules and the extended solid - are important in many areas, e.g. in air pollution, interstellar matter, clay minerals, photography, heterogeneous catalysis, quantum dots, and virus crystals. This book extends the approaches of optical molecular and solid-state methods to clusters, revealing how their optical properties evolve as a function of size. Cluster matter, i.e. extended systems of many clusters - the most frequently occuring form - is also treated. The combination of reviews of experimental techniques, lists of results and detailed descriptions of selected experiments will appeal to experts, newcomers and graduate students in this expanding field.
Download or read book Optical Properties of Small Metal Clusters written by and published by . This book was released on 2015 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mots-clés de l'auteur: Clusters ; Solid rare-gas matrix ; Silver ; Gold ; Pyridine ; Optical absorption ; Fluorescence ; SERS ; Vacuum ; Cryogen.
Download or read book Optical Properties of Size selected Supported Metal Clusters Measured by Cavity Ring down Spectroscopy written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Supported size-selected metal clusters have attracted considerable interest due to their special catalytic properties. Optical spectroscopy is a powerful method to characterise the electronic and geometrical properties of such systems. However, observing the optical properties of these small clusters is not trivial and highly sensitive techniques such as cavity ring-down spectroscopy (CRDS), a method previously used to study gas phase samples, are required. An experimental apparatus capable of studying the optical properties of support size-selected metal clusters is presented here for the first time. The metal clusters were prepared using a state-of-the-art laser ablation source, and size selected prior to deposition onto an optically transparent support material. CRDS was adapted for the study of solid samples over an extended wavelength range and used to investigate the size dependent optical properties of supported metal clusters.
Download or read book Optical Properties of Size selected Supported Metal Clusters Measured by Cavity Ring down Spectroscopy written by Aras Kartouzian and published by . This book was released on 2010 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure and Properties of Atomic Nanoclusters written by Julio A. Alonso and published by World Scientific. This book was released on 2012 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atomic clusters are aggregates of atoms containing a few to several thousand atoms. Due to the small size of these pieces of matter, the properties of atomic clusters in general are different from those of the corresponding material in the macroscopic bulk phase. This monograph presents the main developments of atomic clusters and the current status of the field. The book treats different types of clusters with very different properties: clusters in which the atoms or molecules are tied by weak van der Waals interactions, metallic clusters, clusters of ionic materials, and network clusters made of typical covalent elements. It includes methods of experimental cluster synthesis as well as the structural, electronic, thermodynamic and magnetic properties of clusters, covering both experiments and the theoretical work that has led to our present understanding of the different properties of clusters. The question of assembling nanoclusters to form solids with new properties is also considered. Having an adequate knowledge of the properties of clusters can be of great help to any scientist working with objects of nanometric size. On the other hand, nanoclusters are themselves potentially important in fields like catalysis and nanomedicine.
Download or read book Physics and Chemistry of Small Clusters written by P. Jena and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 932 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent advances in experimental techniques now enable researchers to produce in a laboratory clusters of atoms of desired composition from any of the elements of the periodic table. This has created a new area of research into novel materials since clusters cannot be regarded either as a "large" molecule or as a fragment of the bulk. Both experimental and theoretical studies are revealing unusual properties that are not ob served in solid state environments. The structures of micro-clusters are found to be significantly distorted from the most symmetric arrangement, some even exhibiting pentagonal symmetry commonly found in icosahedric structures. The unusual stability of certain clusters, now described as "magic number species", shows striking similarities with the nuclear shell structure. The relative stabilities of clusters depend not only on the composition of the clusters but also on their charged states. The studies on spontaneous fragmentation of mUltiply charged clusters, commonly referred to as Coulomb explosion, illustrate the role of electronic bonding mechanisms on stability of clusters. The effect of foreign atoms on geometry and stability of clusters and the interaction of gas atoms with clusters are showing promise for an indepth understanding of chemisorption and catalysis. The magnetic and optical properties are dependent not only on cluster size but also on its geometry. These findings have the potential for aiding industry in the area of micro-electronics and catalysis.
Download or read book Optics and Structure of Metal Clusters at the Atomic Scale written by Alfredo Campos Otero and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is well known that the optical properties of nanoparticles of noble metals, in particular gold and silver, deviate strongly from those of macroscopic metals. For sizes between ten and a few hundred nanometers, they are dominated by surface plasmons (SPs) described by purely classical models. On the other hand, clusters of a few tens of atoms behave like quantum systems inducing new optical behaviors. The structure of the nanoparticles and the dielectric environment can affect the optical properties. In this thesis I used a scanning transmission electron microscope (STEM) fitted with an electron energy loss spectrometer (EELS) to measure, in parallel, the optical and structural properties of individual nanoparticles. I present how complementary experiments (STEM-EELS and optical absorption) on sizeselected small silver nanoparticles embedded in silica yield at first inconsistent results: while optical absorption shows no size-effect in the range between only a few atoms and ~10 nm, a clear spectral shift is observed in STEM-EELS technique. Our quantitative interpretation, based on a mixed classical/quantum model which takes into account all the relevant quantum effects, resolves the apparent contradictions, not only within our experimental data, but also in the literature. Our comprehensive model describes how the local environment is the crucial parameter controlling the manifestation or absence of quantum size effects. Secondly, I was interested in the purely classical region through lithographed structures of a few hundred nanometers. Although triangular plasmonic cavities have been widely studied in the literature, a classification in terms of plasmonic modes of breathing and edge was missing. In this study, experimental STEM-EELS results, analytical models and classical simulations enabled us to describe the nature of the different modes.
Download or read book Protected Metal Clusters From Fundamentals to Applications written by and published by Elsevier. This book was released on 2015-09-06 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: Protected Metal Clusters: From Fundamentals to Applications surveys the fundamental concepts and potential applications of atomically precise metal clusters protected by organic ligands. As this class of materials is now emerging as a result of breakthroughs in synthesis and characterization that have taken place over the last few years, the book provides the first reference with a focus on these exciting novel nanomaterials, explaining their formation, and how, and why, they play an important role in the future of molecular electronics, catalysis, sensing, biological imaging, and medical diagnosis and therapy. Surveys the fundamental concepts and potential applications of atomically precise metal clusters protected by organic ligands. Provides well-organized, tutorial style chapters that are ideal for teaching and self-study In-depth descriptions by top scientists in the field Presents the state-of-the art of protected metal clusters and their future prospects
Download or read book Small Particles and Inorganic Clusters written by Claude Chapon and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 555 pages. Available in PDF, EPUB and Kindle. Book excerpt: A lively demonstration of the great vitality and the multidisciplinary character of cluster research and of the usefulness of synthesizing its various aspects was given at this symposium. This volume covers all aspects of the physical and chemical properties of free and supported clusters or small particles: static, dynamical, electronic, magnetic and optical properties, adsorption and chemical phenomena. It thus gives a complete overview of the status of the field and its development.
Download or read book Polymer Films with Embedded Metal Nanoparticles written by Andreas Heilmann and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents an overview of nanostructure determination and ways to find relationships to the electronic and optical properties. The methods described can be applied to a large number of other granular metal-insulator systems and used as a guideline for characterisation and modelling. In addition, the book describes the manufacture of artificially structured nanomaterials using laser or electron-beam irradiation.
Download or read book Contribution of Clusters Physics to Materials Science and Technology written by Joel Davenas and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 649 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the last decade there has been an increasing interest in clusters and small particles because of the peculiar proper ties induced by their large area to volume ratio. For that reason small particles are often considered as an intermediate state of matter at the border between atomic (or molecular) chemistry, and physics of the condensed matter. The importance of the surface effect can explain the anomalous properties, for example the exis tence of the five fold symmetry observed in different circumstan ces '(beams of rare gas clusters, gold particles deposited on a substrate). However the question of the critical size at which the transition to bulk properties occurs cannot be simply answered, since the reply depends on the peculiar property which is studied. The importance of the size effect was emphasized in the last International Meetings. However the situation remains confused in most cases since the exact role of the cluster environment cannot be clearly elucidated and is a main difficulty, except in cluster beam experiments. In fact ideally free clusters constitute a labo ratory exception. In most applications small particles must be supported on a surface or embedded in a matrix, in order to be stabilized, which obviously shows the role of the environment.
Download or read book Atoms Molecules and Clusters in Electric Fields written by George Maroulis and published by Imperial College Press. This book was released on 2006 with total page 694 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the central importance of electric polarizability and hyperpolarizability for a wide spectrum of activities, this book charts the trends in the accurate theoretical determination of these properties in specialized fields. The contributions include reviews and original papers that extend from methodology to applications in specific areas of primary importance such as cluster science and organic synthesis of molecules with specific properties.
Download or read book Metal Clusters at Surfaces written by Karl-Heinz Meiwes-Broer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 315 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to the interaction with the contact medium, the properties of clusters may change or even disappear. Thus the physics of cluster-on-surface systems -- the main subject of this book -- is of fundamental importance. The book addresses a wide audience, from the newcomer to the expert. Starting from fundamental concepts of adsorbate-surface interactions, the modification of electronic properties through electron confinement, and concepts of cluster production, it elucidates the distinct properties of the new metallic nanostructures.
Download or read book Recent Advances In Density Functional Methods Part Ii written by Delano Pun Chong and published by World Scientific. This book was released on 1997-05-14 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: Of all the different areas in computational chemistry, density functional theory (DFT) enjoys the most rapid development. Even at the level of the local density approximation (LDA), which is computationally less demanding, DFT can usually provide better answers than Hartree-Fock formalism for large systems such as clusters and solids. For atoms and molecules, the results from DFT often rival those obtained by ab initio quantum chemistry, partly because larger basis sets can be used. Such encouraging results have in turn stimulated workers to further investigate the formal theory as well as the computational methodology of DFT.This Part II expands on the methodology and applications of DFT. Some of the chapters report on the latest developments (since the publication of Part I in 1995), while others extend the applications to wider range of molecules and their environments. Together, this and other recent review volumes on DFT show that DFT provides an efficient and accurate alternative to traditional quantum chemical methods. Such demonstration should hopefully stimulate frutiful developments in formal theory, better exchange-correlation functionals, and linear scaling methodology.
Download or read book Nanoparticle Assemblies and Superstructures written by Nicholas A. Kotov and published by CRC Press. This book was released on 2016-04-19 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cubes, triangular prisms, nano-acorn, nano-centipedes, nanoshells, nano-whiskers. . . . Now that we can create nanoparticles in a wide variety of shapes and morphologies, comes the next challenge: finding ways to organize this collection of particles into larger and more complex systems. Nanoparticle Assemblies and Superstructures, edit
Download or read book Luminescent Metal Nanoclusters written by Sabu Thomas and published by Woodhead Publishing. This book was released on 2022-06-28 with total page 728 pages. Available in PDF, EPUB and Kindle. Book excerpt: Luminescent Metal Nanoclusters: Synthesis, Characterization, and Applications provides a comprehensive accounting of various protocols used for the synthesis of metal nanoclusters, their characterization techniques, toxicity evaluation and various applications and future prospects. The book provides detailed experimental routes, along with mechanisms on the formation of benign metallic clusters using biomaterials and a comprehensive review regarding the preparation, properties and prospective applications of these nano clusters in various fields, including therapeutic applications. Various methods to protect nanocluster materials to increase their stability are emphasized, including the incorporation of ligands (protein, small molecule, DNA, thiols). This book addresses a gap in the current literature by bringing together the preparation, characterization and applications of all the possible types of reported metal nanoclusters and their hybrids. It is suitable for materials scientists and engineers in academia and those working in research and development in industry. It may also be of interest to those working in the interdisciplinary nanotechnology community, such as physical chemists. Covers the most relevant material categories of luminescent nanoclusters such as metal nanoclusters, nano composites and alloy nanoclusters Provides a comprehensive overview of the various available methods used for the protection of nanoclusters Discusses the latest advances and future opportunities in addressing challenges in producing benign nanomaterials such as toxicity and stability
Download or read book Strategic Research at the Frontiers of Chemistry written by and published by . This book was released on 1995 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
