Download or read book Atomic and Electronic Structure of Metals and Alloys Rare Earths Ultrathin Films and Surface Alloys written by and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Atomic and Electronic Structure of Metals and Alloys written by and published by . This book was released on 1993 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The project has been productive: 47 refereed publications in about 5 years. While confined to the area of surfaces and thin films, the project has covered a wide range of physical properties and different materials: rare earths, bulk and surface alloys, metal surfaces, magnetism, and (especially) atomic and electronic structure of ultrathin films. Notable achievements include quantitative studies of atomic structure of clean rare-earth surfaces: Tb(0001), Tb(11{ovr 2}0), Gd(0001), and Gd(11{ovr 2}0). Surface alloys studied included Cu{l_brace}001{r_brace}c(2 x 2)-Au and Cu{l_brace}001{r_brace}c(2 x 2)-Pd. The most important achievement of the project lies in the application of quantitative low-energy electron diffraction to ultrathin films, particularly magnetic metals on nonmagnetic substrates (e.g., Fe on Ag{l_brace}001{r_brace}, etc.) (No data given.).

Download or read book Atomic and Electronic Structure of Metals and Alloys written by and published by . This book was released on 1990 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this second period of support we have concentrated exclusively on three subjects, namely, (1) rare earths, bulk and surfaces; (2) ultrathin films of strained metallic phases; and (3) improvement of experimental facilities. In the area of rare earths we have analyzed the photoemission data collected at beamline U7B of the National Synchrotron Light Source from a single-crystal platelet of Tb(0001).

Download or read book Atomic and Electronic Structure of Metals and Alloys written by and published by . This book was released on 1991 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The accomplishments of the work done under DOE sponsorship are summarized in the list of publications at the end of this narrative. Here we give a brief description of the nature and the significance of the accomplishments. The activity can be roughly subdivided into three parts: studies of surface alloys, studies of epitaxial ultra-thin films, and studies of electron band structure of metals. The list reflects the developments of particular areas of research and the phasing out of others as this was suggested by the interest in, and the success of, specific experimental projects.

Download or read book Atomic and electronic structures of two dimensional layers on noble metals written by Jalil Shah and published by Linköping University Electronic Press. This book was released on 2019-09-04 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two-dimensional (2D) materials, in the form of a single atomic layer with a crystalline structure, are of interest for electronic applications. Such materials can be formed by a single element, e.g., by group IV or group V elements, or as a 2D surface alloy. As these materials consist of just a single atomic layer, they may have unique properties that are not present in the bulk. The (111) surfaces of the noble metals Ag and Au are important for the preparation of several 2D materials. To investigate the atomic and electronic structures, the following experimental techniques were used in this thesis: angle resolved photoelectron spectroscopy (ARPES), scanning tunneling microscopy (STM) and low energy electron diffraction (LEED). The 2D structures studied in this thesis include arsenene (an As analogue to graphene) and As/Ag(111), Sn/Au(111), and Te/Ag(111) surface alloys. Arsenene has been thoroughly investigated theoretically for many years and several interesting properties important for next generation electronic and optoelectronic devices have been described in the literature. This thesis presents the first experimental evidence of the formation of arsenene. A clean Ag(111) surface was exposed to arsenic in an ultra-high vacuum chamber at an elevated substrate temperature (250 to 350 °C ). The resulting arsenic layer was studied by LEED, STM and ARPES. Both LEED and STM data resulted in a lattice constant of the arsenic layer of 3.6 Å which is consistent with the formation of arsenene. A comparison between the experimental band structure obtained by ARPES and the theoretical band structure of arsenene based on density functional theory (DFT), further verified the formation of arsenene. The As/Ag(111) surface alloy was prepared by exposing clean Ag(111) to arsenic followed by heating to 400 °C. This resulted in an Ag2As surface alloy which formed by the replacement of every third Ag atom by an As atom in a periodic fashion. LEED showed a complex pattern of diffraction spots corresponding to a superposition of three domains of a reconstruction described by a unit cell. STM images revealed a surface with a striped atomic structure with ridges characterized by a local ?3 × ?3 structure. ARPES data showed three alloy related bands of which one can be associated with the ?3 × ?3 structure on the ridges. This band shows a split in momentum space around the point along the direction of a ?3 × ?3 surface Brillouin zone in similarity with a Ge/Ag(111) surface alloy. Sn/Au(111) surface alloys can be prepared with different periodicities. An Au2Sn phase characterized by a ?3 × ?3 periodicity and an Au3Sn phase with a 2 × 2 periodicity are formed containing 0.33 and 0.25 monolayer of Sn, respectively. The clean Au(111) surface itself, shows a complex reconstruction, the so called herringbone structure, that can be viewed as a zig-zag pattern of stripes described by a 22 × ?3 unit cell. The replacement of Au atoms by Sn results in change of the periodicity of the herringbone structure to 26 × ?3 and ? 26 × 2?3 for the Au2Sn and Au3Sn surface alloys, respectively. Furthermore, the local 1 × 1 periodicity of clean Au(111) is replaced by a ?3 × ?3 and a 2 × 2 periodicity as is clear from STM images of the respective cases. ARPES data are presented for the Au2Sn surface alloy, which reveal an electronic band structure with similarities to other striped surface alloys. In particular, the split in momentum space around the point of a ?3 × ?3 surface Brillouin zone is observed also for Au2Sn. A Te-Ag binary surface alloy can be formed by evaporating 1/3 monolayer of Te onto a clean Ag(111) surface followed by annealing. After this preparation, LEED showed sharp ?3 × ?3 diffraction spots that is evidence for a well-ordered surface layer. ARPES data revealed two distinct electronic bands that followed the ?3 × ?3 periodicity. One of these bands showed a small spin-split of the Rashba type. The experimental band structure was compared with the theoretical bands of several atomic models of Te induced structures on Ag(111). An excellent fit was obtained for a Te-Ag surface alloy with a planar honeycomb structure, with one Te and one Ag atom in the unit cell. A semiconducting electronic structure of the Te-Ag surface alloy was inferred from the ARPES data in agreement with the ?0.7 eV band gap predicted by the DFT calculations.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 892 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1995 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Electronic Structure of Alloys Surfaces and Clusters written by Abhijit Mookerjee and published by CRC Press. This book was released on 2002-11-28 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the electronic structure of solids is a basic part of theoretical investigation in physics. Application of investigative techniques requires the solid under investigation to be "periodic." However, this is not always the case. This volume addresses three classes of "non-periodic" solids currently undergoing the most study: alloys, surfaces and clusters. Understanding the electronic structure of these systems is fundamental not only for the basic science, but also constitutes a very important step in various technological aspects, such as tuning their stabilities, chemical and catalytic reactivities and magnetism. Expert practitioners give an up-to-date account of the field with enough detailed background so that even a newcomer can follow the development. The theoretical framework is discussed in addition to the present status of knowledge in the field. Electronic Structure of Alloys, Surfaces and Clusters also includes an extensive bibliography which provides a comprehensive reading list of work on the topic.

Download or read book Electronic Structure of Disordered Alloys Surfaces and Interfaces written by Ilja Turek and published by Springer Science & Business Media. This book was released on 2013-11-27 with total page 327 pages. Available in PDF, EPUB and Kindle. Book excerpt: At present, there is an increasing interest in the prediction of properties of classical and new materials such as substitutional alloys, their surfaces, and metallic or semiconductor multilayers. A detailed understanding based on a thus of the utmost importance for fu microscopic, parameter-free approach is ture developments in solid state physics and materials science. The interrela tion between electronic and structural properties at surfaces plays a key role for a microscopic understanding of phenomena as diverse as catalysis, corrosion, chemisorption and crystal growth. Remarkable progress has been made in the past 10-15 years in the understand ing of behavior of ideal crystals and their surfaces by relating their properties to the underlying electronic structure as determined from the first principles. Similar studies of complex systems like imperfect surfaces, interfaces, and mul tilayered structures seem to be accessible by now. Conventional band-structure methods, however, are of limited use because they require an excessive number of atoms per elementary cell, and are not able to account fully for e.g. substitu tional disorder and the true semiinfinite geometry of surfaces. Such problems can be solved more appropriately by Green function techniques and multiple scattering formalism.

Download or read book Optical Properties and Electronic Structure of Metals and Alloys written by F. Abelès and published by . This book was released on 1966 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Physics of Metals Volume 1 Electrons written by Sir Nevill Francis Mott and published by CUP Archive. This book was released on 1969-07 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: This advanced 1969 treatise was written by a team of international experts, and presents a definitive account of a major field of modern physics.

Download or read book Government Reports Annual Index written by and published by . This book was released on 1994 with total page 1148 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1994 with total page 1142 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Electronic Structure and Reactivity of Metal Surfaces written by E. Derouane and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt: Imagine that a young physicist would approach a granting agen cy and propose to contribute to heterogeneous catalysis by studying the heat conductivity of gases in contact with a hot filament. How would he be received now? How would he have been treated sixty years ago ? Yet, more than sixty years ago, Irving Langmuir, through his study of heat transfer from a tungsten filament, uncovered most of the fundamental ideas which are used to-day by the scientific com munity in pure and applied heterogeneous catalysis. Through his work with what were for the first time "clean" metal surfaces, Langmuir formulated during a period of a little over ten years un til the early thirties, the concepts of chemisorption, monolayer, adsorption sites, adsorption isotherm, sticking probability, cata lytic mechanisms by way of the interaction between chemisorbed spe cies, behavior of non-uniform surfaces and repulsion between adsor bed dipoles. It is fair to say that many of these ideas constituting the first revolution in surface chemistry have since been refined through thousands of investigations. Countless papers have been pu blished on the subject of the Langmuir adsorption isotherm, the Langmuir catalytic kinetics and the Langmuir site-exclusion adsorp tion kinetics. The refinements have been significant. ThE original concepts in their primitive or amended form are used everyday by catalytic chemists and chemical engineers allover the world in their treatment of experimental data, design of reactors or inven tion of new processes.

Download or read book Metal Surface Electron Physics written by A. Kiejna and published by Elsevier. This book was released on 1996-03-15 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the last thirty years metal surface physics, or generally surface science, has come a long way due to the development of vacuum technology and the new surface sensitive probes on the experimental side and new methods and powerful computational techniques on the theoretical side. The aim of this book is to introduce the reader to the essential theoretical aspects of the atomic and electronic structure of metal surfaces and interfaces. The book gives some theoretical background to students of experimental and theoretical physics to allow further exploration into research in metal surface physics.The book consists of three parts. The first part is devoted to classical description of geometry and structure of metal crystals and their surfaces and surface thermodynamics including properties of small metallic particles. Part two deals with quantum-mechanical description of electronic properties of simple metals. It starts from the free electron gas description and introduces the many body effects in the framework of the density functional theory, in order to discuss the basic surface electronic properties of simple metals. This part outlines also properties of alloy surfaces, the quantum size effect and small metal clusters. Part three gives a succinct description of metal surfaces in contact with foreign atoms and surfaces. It treats the work function changes due to alkali metal adsorption on metals, adhesion between metals and discusses the universal aspects of the binding energy curves. In each case extensive reference lists are provided.

Download or read book Atomic and Electronic Structure of Metals written by American Society for Metals and published by . This book was released on 1967 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Atomic Structure and the Strength of Metals written by N. F. Mott and published by Elsevier. This book was released on 2016-05-13 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atomic Structure and the Strength of Metals is a collection of prepared lectures presented at the 1956 Page-Barbour Lectures before the University of Virginia. These lectures are based in part on two lectures given in the University of Cambridge as part of a course designed to present some of the ideas of physics to students of the humanities. The first lecture explores the physics of metals, with a particular emphasis on the properties of metals and their relationship with the properties of atoms. The second lecture describes the behavior of the atoms in a piece of metal when it is bent or pulled out. This lecture highlights the strength of solid, which involves the study of the defects in the crystalline structure. The third lecture discusses the concept and experimental evidence of material dislocation. This lecture provides a model of a polycrystalline metal, in which boundaries between grains appear. This book is directed toward physics students and nonspecialists.