The conventional notion of the crystal field potential is narrowed to its non-spherical part only through ignoring the dominating spherical part which produces only a uniform energy shift of gravity centres of the free ion terms. It is well understood that the non-spherical part of the effective potential "seen" by open-shell electrons localized on a metal ion plays an essential role in most observed properties. Light adsorption, electron paramagnetic resonance, inelastic neutron scattering and basic characteristics derived from magnetic and thermal measurements, are only examples of a much wider class of experimental results dependent on it. The influence is discerned in all kinds of materials containing unpaired localized electrons: ionic crystals, semiconductors and metallic compounds including materials as intriguing as high-Tc superconductors, or heavy fermion systems. It is evident from the above that we deal with a widespread effect relative to all free ion terms except those which can stand the lowered symmetry, e.g. S-terms.
Despite the universality of the phenomenon, the available handbooks on solid state physics pay only marginal attention to it, merely making mention of its occurrence. Present understanding of the origins of the crystal field potential differs essentially from the pioneering electrostatic picture postulated in the twenties. The considerable development of the theory that has been put forward since then can be traced in many regular articles scattered throughout the literature. The last two decades have left their impression as well but, to the authors' best knowledge, this period has not been closed with a more extended review. This has also motivated us to compile the main achievements in the field in the form of a book.
This monograph follows the Greek tradition in seeking beautiful shapes such as regular convex polyhedra. The primary aim is to convey to the reader how algebraic topology is effectively used to explore the rich world of crystal structures. Graph theory, homology theory, and the theory of covering maps are employed to introduce the notion of the topological crystal which retains, in the abstract, all the information on the connectivity of atoms in the crystal. For that reason the title Topological Crystallography has been chosen.
Topological crystals can be described as “living in the logical world, not in space,” leading to the question of how to place or realize them “canonically” in space. Proposed here is the notion of standard realizations of topological crystals in space, including as typical examples the crystal structures of diamond and lonsdaleite. A mathematical view ofthe standard realizations is also provided by relating them to asymptotic behaviors of random walks and harmonic maps. Furthermore, it can be seen that a discrete analogue of algebraic geometry is linked to the standard realizations.
Applications of the discussions in this volume include not only a systematic enumeration of crystal structures, an area of considerable scientific interest for many years, but also the architectural design of lightweight rigid structures. The reader therefore can see the agreement of theory and practice.
The authors provide an introduction to the field of newcomers and a reference to those involved in the various aspects of industrial crystallization. It is a complete volume covering all aspects of industrial crystallization, including material related to both fundamentals and applications. This new edition presents detailed material on crystallization of biomolecules, precipitation, impurity-crystal interactions, solubility, and design.
Provides an ideal introduction for industrial crystallization newcomers
Serves as a worthwhile reference to anyone involved in the field
Covers all aspects of industrial crystallization in a single, complete volume
Reinforcing its unrivalled position as the core text for teaching crystallography and crystal defects, each chapter includes problem sets with brief numerical solutions at the end of the book. Detailed worked solutions, supplementary lecture material and computer programs for crystallographic calculations are provided online (http://booksupport.wiley.com).
* Collects the latest research on the chemistry of complex fluorides and oxyfluorides of Tantalum and Niobium.
* Covers both theory and application of Tantalum and Niobium Fluoride Chemistry
* Is suitable for tantalum and niobium producers, researchers studying the chemistry of fluorides, as well as teachers and students in chemistry and metallurgy
The rapid growth of interest in hopping transport has followed in the footsteps of the development of physics of disordered systems during the last three decades. The intense interest in disordered solids can be attributed to the technological potential of the new noncrystalline materials, as well as to new fundamental problems discovered in solid state physics when a crystal is no longer translationally symmetric.
In the last decade hopping systems such as organic polymers, biological materials, many oxide glasses, mesoscopic systems, and the new high-temperature superconducting materials in their normal state have attracted much interest. New phenomena investigated recently include interference and coherent scattering in variable range hopping conduction, mesoscopic effects, relaxation processes and thermo-electric power, and thermal conductivity caused by hopping transport. This volume presents the reader with a thorough overview of these recent developments, written by leading experts in the various fields.
Comprised of 20 chapters, this volume begins with a discussion on the formal theory of anelasticity, and then explores the anelastic behavior, which is a manifestation of internal relaxation process. This text lays the groundwork for the formal theory by introducing the postulates. Other chapters explore the different dynamical methods that are frequently used in studying anelasticity. The reader is then introduced to the physical origin of anelastic relaxation process in terms of atomic model. This text also discusses the various types of point defects in crystals, including elementary point defects, composite defects, and self-interstitial defects. The final chapter provides relevant information on the various frequency ranges used in the study.
This book is intended for crystallographers, mechanical engineers, metallurgical engineers, solid-state physicists, materials scientists, and researchers.
Drawing on years of research and teaching experience, Eaton E. Lattman and Patrick J. Loll use clear examples and abundant illustrations to provide a concise and accessible primer on protein crystallography. Discussing the basics of diffraction, the behavior of two- and three-dimensional crystals, phase determination (including MIR and MAD phasing and molecular replacement), the Patterson function, and refinement, Lattman and Loll provide a complete overview of this important technique, illuminated by physical insights.
The crisp writing style and simple illustrations will provide beginner crystallographers with a guide to the process of unraveling protein structure.
The book contains a detailed discussion of the origin and possible sources of anchoring energy in nematic liquid crystals, emphasizing the dielectric contribution to the anchoring energy in particular. Beginning with fundamental surface and anchoring properties of liquid crystals and the definition of the nematic phase, the authors explain how selective ion adsorption, dielectric energy density, thickness dependence, and bias voltage dependence influence the uniform alignment of liquid crystals and affect the performance of liquid crystal devices. They also discuss fundamental equations regulating the adsorption phenomenon and the dynamic aspects of ion adsorption phenomenon in liquid crystalline systems.
Adsorption Phenomena and Anchoring Energy in Nematic Liquid Crystals serves as an excellent source of reference for graduates and researchers working in liquid crystals, complex fluids, condensed matter physics, statistical physics, chemical engineering, and electronic engineering, as well as providing a useful general introduction to and background information on the nematic liquid crystal phase.
Powder diffraction today is used in X-ray and neutron diffraction, where it is a powerful method in neutron diffraction for the determination of magnetic structures. In the last decade the interest has dramatically improved. There is hardly any field of crystallography where the Rietveld, or full pattern method has not been tried with quantitative phase analysis the most important recent application.
Catalytic reactions also proceed in the solid state. Moreover, the solid-state reactions are more economical and ecologically sound. In the future, pollution-free synthetic procedures in the solid state will become increasingly important, not only in chemical industries but also in university laboratories.
This book is the first to give an overview of the scientific and applicative aspects of the entire class of thermochromic and thermotropic materials. It discusses the origin of the thermo-optical effects at the molecular level and presents the macroscopic optical and material properties of chromogenic materials as well as their present and potential future application. With a view to particular potential applications, the book outlines the specific development strategies of these materials.
The book addresses scientific and application-oriented researchers as well as students in the fields of smart adaptive polymers and sun-protecting materials. By providing the fundamental knowledge and outlining the future trends of thermochromism, this book familiarizes the readers with the entire field of the phenomenon.
This book brings together two sets of related articles describing advances made in crystal growth science and technology since World War II. One set is from the proceedings of a Symposium held in August 2002 to celebrate 50 years of progress in the field of crystal growth. The second contains articles previously published in the newsletter of the American Association for Crystal Growth in a series called "Milestones in Crystal Growth".
The first section of this book contains several articles which describe some of the early history of crystal growth prior to the electronics revolution, and upon which modern crystal growth science and technology is based. This is followed by a special article by Prof. Sunagawa which provides some insight into how the successful Japanese crystal growth industry developed. The next section deals with crystal growth fundamentals including concepts of solute distribution, interface kinetics, constitutional supercooling, morphological stability and the growth of dendrites. The following section describes the growth of crystals from melts and solutions, while the final part involves thin film growth by MBE and OMVPE.
These articles were written by some of the most famous theorists and crystal growers working in the field. They will provide future research workers with valuable insight into how these pioneering discoveries were made, and show how their own research and future devices will be based upon these developments.
· Articles written by some of the most famous theorists and crystal growers working in the field
· Valuable insight into how pioneering discoveries were made.
· Show how their own research and future devices will be based upon these developments
The publication first underscores the defects in crystals, detection of defects, and growth and dissolution of crystals. Discussions focus on thermodynamic theories, nature of pit sites, surface roughening during diffusion-controlled dissolution, growth controlled by simultaneous mass transfer and surface reactions, and chemical and thermal etching. The text then examines the theories of dissolution and etch-pit formation and the chemical aspects of the dissolution process, including catalytic reactions, dissolution of semiconductors, topochemical adsorption theories, and diffusion theories.
The book tackles the solubility of crystals and complexes in solution and the kinetics and mechanism of dissolution. Topics include metallic crystals, semiconductors, stability of complexes, relationship between solubility, surface energy, and hardness of crystals, and solvents for crystals and estimation of crystal solubility in solvents other than water.
The publication is a dependable source of data for readers interested in the etching of crystals.
The approach taken in this text, is to introduce the basic continuum theory for nematic liquid crystals in equilibria, then it proceeds to simple application of this theory- in particular, there is a discussion of electrical and magnetic field effects which give rise to Freedericksz transitions, which are important in devices. This is followed by an account of dynamic theory and elementary viscometry of nemantics Discussions of backflow and flow-induced instabilities are also included. Smetic theory is also briefly introduced and summarised with some examples of equilibrium solutions as well as those with dynamic effects. A number of mathematical techniques, such as Cartesian tensors and some variational calculus, are presented in the appendices.
Glass, written by a team of renowned researchers and experienced book authors in the field, presents general features of glasses and glass transitions. Different classes of glassforming systems, such as silicate glasses, metallic glasses, and polymers, are exemplified. In addition, the wide field of phase formation processes and their effect on glasses and their properties is studied both from a theoretical and experimental point of view.
Differences between H-bond and van der Waals interactions from one side and covalent bonds from the other
Bader theory to analyze H-bonding
Influence of weak H-bonds upon structure and function of biological molecules
H-bonds in crystal structures
With contributions from some of the foremost experts in this field this volume provides an invaluable resource for all members of the academic community looking for a comprehensive text on hydrogen bonding. It will be of particular interest to physical and theoretical chemists, spectroscopists, crystallographers and those involved with chemical physics.