Diffuse Scattering and Defect Structure Simulations


Book Description

Understanding the atomic structure of complex and time disordered materials relies upon computer simulations of these structures. This cook book provides a unique mixture of simulation know-how and hands on examples. All related files and the program DISCUS are included on a CDROM with the book.




Structure Analysis by Small-Angle X-Ray and Neutron Scattering


Book Description

Small-angle scattering of X rays and neutrons is a widely used diffraction method for studying the structure of matter. This method of elastic scattering is used in various branches of science and technology, includ ing condensed matter physics, molecular biology and biophysics, polymer science, and metallurgy. Many small-angle scattering studies are of value for pure science and practical applications. It is well known that the most general and informative method for investigating the spatial structure of matter is based on wave-diffraction phenomena. In diffraction experiments a primary beam of radiation influences a studied object, and the scattering pattern is analyzed. In principle, this analysis allows one to obtain information on the structure of a substance with a spatial resolution determined by the wavelength of the radiation. Diffraction methods are used for studying matter on all scales, from elementary particles to macro-objects. The use of X rays, neutrons, and electron beams, with wavelengths of about 1 A, permits the study of the condensed state of matter, solids and liquids, down to atomic resolution. Determination of the atomic structure of crystals, i.e., the arrangement of atoms in a unit cell, is an important example of this line of investigation.




Electron Scattering for Nuclear and Nucleon Structure


Book Description

Scattering of high-energy electrons from nuclear and nucleon targets essentially provides a microscope for examining the structure of these tiny objects. This 2001 book examines the motivation for electron scattering, develops the theoretical analysis of the process and summarises present experimental capabilities. Suitable for advanced undergraduates, graduates and researchers.




Multiple Scattering Theory


Book Description

In 1947, it was discovered that multiple scattering theory (MST) can be used to solve the Schröedinger equation for the stationary states of electrons in a solid. Written by experts in the field, J S Faulkner, G Malcolm Stocks and Yang Wang, this book collates the results of numerous studies in the field of MST and provides a comprehensive, systematic approach to it. For many scientists, students and engineers working with multiple scattering programmes, this will be a useful guide to help expand the existing knowledge of MST as well as understanding its future implications.




Principles of Quantum Scattering Theory


Book Description

Scattering is one of the most powerful methods used to study the structure of matter, and many of the most important breakthroughs in physics have been made by means of scattering. Nearly a century has passed since the first investigations in this field, and the work undertaken since then has resulted in a rich literature encompassing both experimental and theoretical results. In scattering, one customarily studies collisions among nuclear, sub-nuclear, atomic or molecular particles, and as these are intrinsically quantum systems, it is logical that quantum mechanics is used as the basis for modern scattering theory. In Principles of Quantum Scattering Theory, the author judiciously combines physical intuition and mathematical rigour to present various selected principles of quantum scattering theory. As always in physics, experiment should be used to ultimately validate physical and mathematical modelling, and the author presents a number of exemplary illustrations, comparing theoretical and experimental cross sections in a selection of major inelastic ion-atom collisions at high non-relativistic energies. Quantum scattering theory, one of the most beautiful theories in physics, is also very rich in mathematics. Principles of Quantum Scattering Theory is intended primarily for graduate physics students, but also for non-specialist physicists for whom the clarity of exposition should aid comprehension of these mathematical complexities.




The Structure of the Proton


Book Description

This graduate/research level book describes our present knowledge of protons and neutrons, the particles which make up the nucleus of the atom. Experiments using high energy electrons, muons and neutrinos reveal the proton as being made up of point-like constituents, quarks. The strong forces which bind the quarks together are described in terms of the modern theory of quantum chromodynamics (QCD), the â€~glue' binding the quarks being mediated by new constituents called gluons. Larger and new particle accelerators probe the interactions between quarks and gluons at shorter distances. The understanding of this detailed substructure and of the fundamental forces responsible is one of the keys to unravelling the physics of the structure of matter. This book will be of interest to all theoretical and experimental particle physicists.




Scattering and Structures


Book Description

Quantum physics may appear complicated, especially if one forgets the "big picture" and gets lost in the details. However, it can become clearer and less tangled if one applies a few fundamental concepts so that simplified approaches can emerge and estimated orders of magnitude become clear. Povh and Rosina’s Scattering and Structures presents the properties of quantum systems (elementary particles, nucleons, atoms, molecules, quantum gases, quantum liquids, stars, and early universe) with the help of elementary concepts and analogies between these seemingly different systems. In this new edition, sections on quantum gases and an up to date overview of elementary particles have been added.




Multiple Scattering in Solids


Book Description

A description of general techniques for solving linear partial differential equations by dividing space into regions to which the equations are independently applied and then assembling a global solution from the partial ones. Intended for researchers and graduates involved in calculations of the electronic structure of materials, this will also be of interest to workers in quantum chemistry, electron microscopy, acoustics, optics, and other fields. The book begins with an intuitive approach to scattering theory and then turns to partial waves and a formal development of multiple scattering theory, with applications to the solid state. The authors then present a variational derivation of the formalism and an augmented version of the theory, concluding with a discussion of the relativistic formalism and a discussion of the Poisson equation. Appendices discuss Green's functions, spherical functions, Moller operators and the Lippmann-Schwinger equation, irregular solutions, and singularities in Green's functions.




Dynamics of Gas-Surface Scattering


Book Description

Dynamics of Gas-Surface Scattering deals with the dynamics of scattering as inferred from known properties of gases and solids. This book discusses measurements of spatial distributions of scattered atomic and molecular streams, and of the energy and momentum which gas particles exchange at solid surfaces. It also considers two regimes of scattering, both of which are associated with a lower range of incident gas energies: the thermal and structure scattering regimes. Comprised of 10 chapters, this book opens with a brief historical overview of the early experiments that investigated the dynamics of scattering of gases by surfaces. The discussion then turns to some elements of the kinetic theory of gases; intermodular potentials and interaction regimes; and classical-mechanical lattice models used in gas-surface scattering theory. The applications of molecular beams to the study of gas-surface scattering phenomena are also described. The remaining chapters focus on experiments and theories on scattering of molecular streams by surfaces of solids, with emphasis on thermal and structure regimes of inelastic scattering; quantum theory of gas-surface scattering; and quantum mechanical scattering phenomena. This text concludes with an analysis of energy exchange processes that may occur when a solid surface is completely immersed in a still gas. This monograph will be a valuable resource for students and practitioners of physics, chemistry, and applied mathematics.




Electron Scattering in Solid Matter


Book Description

Addressing graduate students and researchers, this book gives a very detailed theoretical and computational description of multiple scattering in solid matter. Particular emphasis is placed on solids with reduced dimensions, on full potential approaches and on relativistic treatments. For the first time approaches such as the screened Korringa-Kohn-Rostoker method are reviewed, considering all formal steps such as single-site scattering, structure constants and screening transformations, and also the numerical point of view. Furthermore, a very general approach is presented for solving the Poisson equation, needed within density functional theory in order to achieve self-consistency. Special chapters are devoted to the Coherent Potential Approximation and to the Embedded Cluster Method, used, for example, for describing nanostructured matter in real space. In a final chapter, physical properties related to the (single-particle) Green's function, such as magnetic anisotropies, interlayer exchange coupling, electric and magneto-optical transport and spin-waves, serve to illustrate the usefulness of the methods described.