New Developments In Crystal Growth

This volume deals with the technologies of crystal fabrication, of crystal machining, and of epilayer production and is the first book on industrial and scientific aspects of crystal and layer production. Highest-quality crystals and epitaxical layers form the base for many of industries technological advances, including telecommunication, computer and electric energy technology, and those technologies based on lasers and nonlinear-optic crystals. Furthermore, automobile electronics, audiovisual equipment and infrared night-vision all depend on high-quality crystals and epilayers, as do novel technologies currently in development and planned for the future.

This book contains 29 contributions of leading crystal technologists covering the following topics: General aspects of crystal growth technology Silicon Compound semiconductors Oxides and halides Crystal machining Epitaxy and layer deposition

Scientific and technological problems of production and machining of industrial crystals are discussed by top experts, most of the m from the major growth industries and crystal growth centres.

It is anticipated that this volume will serve all scientists and engineers involved in crystal and epilayer fabrication. In addition, it will be useful for the users of crystals, for teachers and graduate students in materials sciences, in electronic and other functional materials, chemical and metallurgical engineering, micro-and optoelectronics including nanotechnology, mechanical engineering and precision-machining, microtechnology, and in solid-state sciences. Also consultants and specialists will profit from this book, as will those interested in crystals, epilayers, and their productionfor saving energy (GaN- and SiC-based high-power electronics and light-emitting diodes for illumination) and for renewable energy sources (economic high-efficiency solar cells and forthcoming laser-fusion energy).

Superb study begins with fundamentals of x-ray diffraction theory using Fourier transforms, then applies general results to various atomic structures, amorphous bodies, crystals and imperfect crystals. Elementary laws of X-ray diffraction on crystals follow as special case. Highly useful for solid-state physicists, metallographers, chemists and biologists. 1963 edition. 154 illustrations. Appendixes. Index.

This book is designed to help those with little or no background in the field of defect chemistry to apply its principles and to interpret the related behaviour of materials. It is the product of a course for advanced undergraduates and graduate students that the author taught at Lehigh University for over twenty years. The course is highly interdisciplinary and has been attended by students from the departments of chemical engineering, chemistry, electrical engineering, computer science, geology, materials science and engineering, and physics. The book is intended for use either as a text on such a course, or as a reference work that covers the major principles of defect chemistry.

This book is by far the most comprehensive treatment of point and space groups, and their meaning and applications. Its completeness makes it especially useful as a text, since it gives the instructor the flexibility to best fit the class and goals. The instructor, not the author, decides what is in the course. And it is the prime book for reference, as material is much more likely to be found in it than in any other book; it also provides detailed guides to other sources.Much of what is taught is folklore, things everyone knows are true, but (almost?) no one knows why, or has seen proofs, justifications, rationales or explanations. (Why are there 14 Bravais lattices, and why these? Are the reasons geometrical, conventional or both? What determines the Wigner-Seitz cells? How do they affect the number of Bravais lattices? Why are symmetry groups relevant to molecules whose vibrations make them unsymmetrical? And so on). Here these analyses are given, interrelated, and in-depth. The understanding so obtained gives a strong foundation for application and extension. Assumptions and restrictions are not merely made explicit, but also emphasized.In order to provide so much information, details and examples, and ways of helping readers learn and understand, the book contains many topics found nowhere else, or only in obscure articles from the distant past. The treatment is (often completely) different from those elsewhere. At least in the explanations, and usually in many other ways, the book is completely new and fresh. It is designed to inform, educate and make the reader think. It strongly emphasizes understanding.The book can be used at many levels, by many different classes of readers - from those who merely want brief explanations (perhaps just of terminology), who just want to skim, to those who wish the most thorough understanding. remove remove

This classic text of elementary dislocation theory has been reprinted to fulfil persistent demand. Yet because it approaches elementary dislocation theory from its most basic level, the material contained in the volume is as up-to-date as when first published. The text addresses topics which are fundamental to the theory of dislocation behaviour, such as Burgers vectors and internal stresses of dislocations.

Concise, logical, and mathematically rigorous, this introduction to the theory of dislocations is addressed primarily to students and researchers in the general areas of mechanics and applied mathematics. Its scope encompasses those aspects of dislocation theory which are closely related to the theories of elasticity and macroscopic plasticity, to modern continuum mechanics, and to the theory of cracks and fracture. The volume incorporates several new and original pieces of work, including a development of the theory of dislocation motion and plastic strain for non-linear materials, a new discussion of the line tension model, revised calculations of the Peierls resistance, and a new development of the van der Merwe theory of crystal interfaces.

The study of solids is one of the richest, most exciting, and most successful branches of physics. While the subject of solid state physics is often viewed as dry and tedious this new book presents the topic instead as an exciting exposition of fundamental principles and great intellectual breakthroughs. Beginning with a discussion of how the study of heat capacity of solids ushered in the quantum revolution, the author presents the key ideas of the field while emphasizing the deep underlying concepts. The book begins with a discussion of the Einstein/Debye model of specific heat, and the Drude/Sommerfeld theories of electrons in solids, which can all be understood without reference to any underlying crystal structure. The failures of these theories force a more serious investigation of microscopics. Many of the key ideas about waves in solids are then introduced using one dimensional models in order to convey concepts without getting bogged down with details. Only then does the book turn to consider real materials. Chemical bonding is introduced and then atoms can be bonded together to crystal structures and reciprocal space results. Diffraction experiments, as the central application of these ideas, are discussed in great detail. From there, the connection is made to electron wave diffraction in solids and how it results in electronic band structure. The natural culmination of this thread is the triumph of semiconductor physics and devices. The final section of the book considers magnetism in order to discuss a range of deeper concepts. The failures of band theory due to electron interaction, spontaneous magnetic orders, and mean field theories are presented well. Finally, the book gives a brief exposition of the Hubbard model that undergraduates can understand. The book presents all of this material in a clear fashion, dense with explanatory or just plain entertaining footnotes. This may be the best introductory book for learning solid state physics. It is certainly the most fun to read.

X-ray scattering is a well-established technique in materials science. Several excellent textbooks exist in this field, but these texts are typically written by physicists who use mathematics to make things clear. Consequently these books appeal less to students and scientists in the field of soft matter (polymers, liquid crystals, colloids, self-assembled organic systems) who usually have a more chemical-oriented background with limited mathematics. Moreover, they need to know about the technique of x-ray scattering, but do not intend to become an expert. The aim of this book is to explain basic principles and applications of x-ray scattering in a simple way using many practical examples followed by more elaborate case studies. The book contains a separate chapter on the different types of order/disorder in soft matter that play such an important role in modern self-assembling systems. Finally the last chapter treats soft matter surfaces and thin film that are increasingly used in coatings and in many technological applications, such as liquid crystal displays and nanostructured block copolymer films. This book has been written for the large community of soft matter students and scientists.

The study of solids is one of the richest, most exciting, and most successful branches of physics. While the subject of solid state physics is often viewed as dry and tedious this new book presents the topic instead as an exciting exposition of fundamental principles and great intellectual breakthroughs. Beginning with a discussion of how the study of heat capacity of solids ushered in the quantum revolution, the author presents the key ideas of the field while emphasizing the deep underlying concepts. The book begins with a discussion of the Einstein/Debye model of specific heat, and the Drude/Sommerfeld theories of electrons in solids, which can all be understood without reference to any underlying crystal structure. The failures of these theories force a more serious investigation of microscopics. Many of the key ideas about waves in solids are then introduced using one dimensional models in order to convey concepts without getting bogged down with details. Only then does the book turn to consider real materials. Chemical bonding is introduced and then atoms can be bonded together to crystal structures and reciprocal space results. Diffraction experiments, as the central application of these ideas, are discussed in great detail. From there, the connection is made to electron wave diffraction in solids and how it results in electronic band structure. The natural culmination of this thread is the triumph of semiconductor physics and devices. The final section of the book considers magnetism in order to discuss a range of deeper concepts. The failures of band theory due to electron interaction, spontaneous magnetic orders, and mean field theories are presented well. Finally, the book gives a brief exposition of the Hubbard model that undergraduates can understand. The book presents all of this material in a clear fashion, dense with explanatory or just plain entertaining footnotes. This may be the best introductory book for learning solid state physics. It is certainly the most fun to read.

Fibre (rod) and sheet-shaped crystals with specified size for use as final products without additional machining are required in various applications of modern engineering. In order to avoid formation of internal mechanical stress in the crystal, lateral surface shaping without contact with container walls is preferred. As the crystal is not restricted by crucible walls, its cross-section is determined by the meniscus-shaping capillary forces and the heat and mass-exchange in the melt-crystal system. Any variation of the pulling rate, pressure, temperature gradient in the furnace, and melt temperature at the meniscus base leads to a change in the crystal cross-section and to pinch formation. Over the past two decades, many experimental and theoretical studies have been reported on a powerful approach to crystal lateral surface shaping without contact with container walls, namely the so-called edge-defined film-fed growth (EFG) technique. The shape and size of a single crystal grown by EFG is determined by the shape and size of the meniscus, (i.e: the liquid bridge retained between the die and the crystal) which depend on the radius or half-thickness of the die and other properties such as pulling rate, pressure, temperature gradient and melt temperature. In this book, theoretical and numerical results are obtained using a non-linear mathematical model of the EFG method. Theoretical results presented for fibres and sheets are rigorously obtained on the basis of the equations of the model. Numerical results are obtained on the basis of theoretical results using experimental data. Such results offer a complete package of the possibilities of the model for equipment designers and practical crystal growers.

Experimental and theoretical aspects of crystal growth and its applications, e.g. in devices, are within the scope of these new books . Experimental and theoretical contributions are included in the following fields: theory of nucleation and growth, molecular kinetics and transport phenomena, crystallisation in viscous media such as polymers and glasses; crystal growth of metals, minerals, semiconductors, superconductors, magnetics, inorganic, organic and biological substances in bulk or as thin films; molecular beam epitaxy, chemical vapour deposition, growth of III-V and II-VI and other semiconductors; characterisation of single crystals by physical and chemical methods; apparatus, instrumentation and techniques for crystal growth, and purification methods; multi-layer heterostructures and their characterisation with an emphasis on crystal growth and epitaxial aspects of electronic materials.

The three-dimensional aspects of molecular shape can be crucial to both properties and reactions. The Third Dimension explores the arrangements of atoms in molecules and in different types of solids. Initial chapters describe the common crystal structures and how they are related to close-packed arrangements of ions. Metallic, ionic, molecular and extended covalent crystals are covered; major types of crystal defects are also discussed. The book then introduces isomerism, and explores the stereochemical consequences of the tetrahedral carbon atom. Chirality is also investigated. The book concludes with a Case Study on Liquid Crystals, which describes structures, properties and applications. As visualisation in 3D is an important part of this book, the accompanying CD-ROMs provide video material, interactive questions and exercises using models to aid understanding of crystals, organic molecules and stereochemistry. All necessary programs are provided. The Molecular World series provides an integrated introduction to all branches of chemistry for both students wishing to specialise and those wishing to gain a broad understanding of chemistry and its relevance to the everyday world and to other areas of science. The books, with their Case Studies and accompanying multi-media interactive CD-ROMs, will also provide valuable resource material for teachers and lecturers. (The CD-ROMs are designed for use on a PC running Windows 95, 98, ME or 2000.)

The last ten years have seen a revolution in our understanding of the mechanisms of biological crystal growth. While it had long been assumed that crystallisation would occur by the same classical mechanisms which form the basis for most descriptions of crystallisation processes, it is now becoming apparent that this is not the case. There are a number of key observations which have changed our view of crystallisation mechanisms. While it had long been assumed that crystalline biominerals typically form by ion-by-ion growth, it is now recognised that they often precipitate via amorphous precursor phases. This is well established for calcium carbonate and there is growing evidence that biogenic crystalline calcium phosphate phases may form via an analogous route. Recent re-examination of the structure of many calcium carbonate biominerals is also suggesting that "non-classical" crystallisation pathways, where crystals grow from the assembly of precursor particles, may also be widespread. Significantly, these mechanisms are not unique to the biological world. Possibly partly inspired by the identification of these biogenic mineralisation strategies, there is currently great interest from the general crystal growth community in these new and controversial ideas. A number of studies on crystal nucleation have recently re-examined classical nucleation theory, and the observation of pre-nucleation clusters is a recurrent theme of great interest. This controversial result apparently contradicts classical nucleation theory which leads the subject of crystal nucleation and growth via assembly to demand attention. The Scientific Committee warmly invites you to take part in this thought-provoking Discussion and looks forward to welcoming you to Leeds.

Chemical crystallography is the study of the principles of chemistry behind crystals and their use in describing structure-property relations in solids. The principles that govern the assembly of crystal and glass structures are described, models of many of the technologically important crystal structures are studied, and the effect of crystal structure on the various fundamental mechanisms responsible for many physical properties are discussed. This new book presents and reviews data on the co-ordination chemistry of several metal complexes with dipicolinic acid and the crystal structure of some anti-malarial metal complexes.

A comprehensive resource book providing professionals and students with a broad survey of structural information delineating the parallel development of crystallography and modern chemistry. Provides detailed description of crystal structures in increasing levels of complexity, from metals to organics, inorganics, organometallics, and inclusion compounds. Examples used to illustrate topics have been carefully selected to reflect the major advances of recent years and to bring the reader to the forefront of active research by including topics of current interest.

Crystal structures and their associated electronic features play an enormous role in chemistry, constituting the most fundamental basis for analyzing and predicting properties of solid-state materials. In Crystal Structure: Properties, Characterization and Determination, the authors begin by discussing some of the refining models and X-ray data treatments for single-crystals containing heavy atoms, such as transition metals or lanthanides.Valuable information on crystal structures and microstructures may be obtained from the observation of high-resolution images if conditions associated iwth crystal thickness and defocus values are satisfied. These images include information not only on accurate atomic coordinates of cations but also on the ordered arrangements of oxygen atoms and oxygen vacancies.In the concluding study, measurements of the heat capacity of Y3-xErxAl5O12 (x=0,0.6,1.1,3), and mixed Er3-xTmx Al5O12, (x=0,1,2,3) and Er2HoAl5O12 solid solutions were carried out in the temperature range of 1.9 to 220 K in magnetic fields up to 9T. The findings suggest that heat capacity variations at low temperatures were impacted by Schottky anomalies.

A photonic crystal fiber (also called microstructure fiber, holey fiber, holeassisted fiber, or micro-structured optical fiber, etc.) is a single material optical fiber which obtains its waveguide properties from an arrangement of very tiny and closely spaced airholes which go through the whole length of the fiber. Unlike the traditional fiber, both the core and cladding are made from the same material in PCFs and light can be well confined and guided properly through the fiber by the mechanism of either total internal reflection (TIR) or photonic band gap (PBG). This book discusses the characteristics, performance and applications of photonic crystals. Chapter One reviews the design characteristics and optical properties. Chapter Two studies band structure of metal/dielectric photonic crystals. Chapter Three describes the splitting method in multicore photonic crystal fiber (PCF). Chapter Four focuses on switches, isolators, circulators, and multifunctional components for optical and THz regions based on 2D photonic crystals with magneto-optical resonators.

The book presents a unified and self-sufficient and reader-friendly introduction to the anisotropic elasticity theory necessary to model a wide range of point, line, planar and volume type crystal defects (e.g., vacancies, dislocations, interfaces, inhomogeneities and inclusions).The necessary elasticity theory is first developed along with basic methods for obtaining solutions. This is followed by a detailed treatment of each defect type. Included are analyses of their elastic fields and energies, their interactions with imposed stresses and image stresses, and the interactions that occur between them, all employing the basic methods introduced earlier.All results are derived in full with intermediate steps shown, and 'it can be shown' is avoided. A particular effort is made to describe and compare different methods of solving important problems. Numerous exercises (with solutions) are provided to strengthen the reader's understanding and extend the immediate text.In the 2nd edition an additional chapter has been added which treats the important topic of the self-forces that are experienced by defects that are extended in more than one dimension. A considerable number of exercises have been added which expand the scope of the book and furnish further insights. Numerous sections of the book have been rewritten to provide additional clarity and scope.The major aim of the book is to provide, in one place, a unique and complete introduction to the anisotropic theory of elasticity for defects written in a manner suitable for both students and professionals.

The book presents a unified and self-sufficient and reader-friendly introduction to the anisotropic elasticity theory necessary to model a wide range of point, line, planar and volume type crystal defects (e.g., vacancies, dislocations, interfaces, inhomogeneities and inclusions).The necessary elasticity theory is first developed along with basic methods for obtaining solutions. This is followed by a detailed treatment of each defect type. Included are analyses of their elastic fields and energies, their interactions with imposed stresses and image stresses, and the interactions that occur between them, all employing the basic methods introduced earlier.All results are derived in full with intermediate steps shown, and 'it can be shown' is avoided. A particular effort is made to describe and compare different methods of solving important problems. Numerous exercises (with solutions) are provided to strengthen the reader's understanding and extend the immediate text.In the 2nd edition an additional chapter has been added which treats the important topic of the self-forces that are experienced by defects that are extended in more than one dimension. A considerable number of exercises have been added which expand the scope of the book and furnish further insights. Numerous sections of the book have been rewritten to provide additional clarity and scope.The major aim of the book is to provide, in one place, a unique and complete introduction to the anisotropic theory of elasticity for defects written in a manner suitable for both students and professionals.

The Atlas-monograph presents a novel approach to the study of the development of snow cover based on its crystal morphology and the fundamental laws of natural symmetry. The Atlas displays more than 320 microphotos of crystals of depth hoar and newly fallen, wind-transported, and small- and medium-grained snow in various mountain and flatland regions of Russia. The principal types of geometrical symmetry are shown along with the phase forms of crystal growth and decomposition and constructive and regressive metamorphism in both loose and dense snow. Illustrated are the morphological features of contact interaction between particles in crystal aggregates under free and tightly packed conditions of growth. Phototables of crystals are furnished with schematics and essential explanatory comments underscoring the most important crystal-morphological features of the hydrothermal fields and the fields of deforming stresses in the snowpack. The presented conceptual model describes the unclosed sublimation-metamorphic evolution cycle of seasonal snow cover and the regional variants of this cycle as its polymorphic (in that number regional) modifications. This model serves as a cornerstone of evolutionary concept. Snow cover is represented as a natural community of the shapes of growing crystals interacting with each other and exposed to environmental influences. It is worked out of the empirical deterministic models describing the sublimation-metamorphic cycle of seasonal snow cover and the polymorphic variants of this cycle. The main driving force of processes yielding an evolutionary row of crystals is the internal interactions within a snow pack. For all that the factor of time (the age of the genetic player) plays a crucial role in sublimation metamorphism. Stadiality of the forms of crystal growth and self-development snow layers are revealed. They are a result of the successive process of superposition of ice crystal-chemical symmetry and dissymmetry of the whole system. Soil-snow-atmosphere, according to the known P. Curie principle. The book is intended for glaciologists and snow scientists employed in the study of the structure of snow cover and in avalanche forecasting as well as for specialists in the field of mineralogical crystallography and crystal growth.

The book intends to give a state-of-the-art overview of flexoelectricity, a linear physical coupling between mechanical (orientational) deformations and electric polarization, which is specific to systems with orientational order, such as liquid crystals.Chapters written by experts in the field shed light on theoretical as well as experimental aspects of research carried out since the discovery of flexoelectricity. Besides a common macroscopic (continuum) description the microscopic theory of flexoelectricity is also addressed. Electro-optic effects due to or modified by flexoelectricity as well as various (direct and indirect) measurement methods are discussed. Special emphasis is given to the role of flexoelectricity in pattern-forming instabilities.While the main focus of the book lies in flexoelectricity in nematic liquid crystals, peculiarities of other mesophases (bent-core systems, cholesterics, and smectics) are also reviewed. Flexoelectricity has relevance to biological (living) systems and can also offer possibilities for technical applications. The basics of these two interdisciplinary fields are also summarized.

This book brings together new leading-edge research on bosons, ferromagnetism and crystal growth.