Yoshio Waseda – författare

A broad array of new engineered materials, with intricate atomic and molecular architecture for sophisticated functional applications in the computer and electronics industries, is under development. For this purpose, there is an urgent need for novel methods for precisely controlling the morphology of particulate materials. This book represents an extended introductory treatise on the fundamental aspects, new methods for the precise control of morphology (size, shape, composition, structure etc.) and accurate materials characterization, from both the basic science and the applied engineering viewpoints. This is the first major compilation of new advances covering the current status and topics related to the processing and production of precisely controlled materials. It provides a unique source of information and guidance for specialists and non-specialists alike.

In this volume we aim to introduce recent progress in the study of aperiodic materials, which include icosahedral clusters, amorphous metals, quasicrys- tals, glasses, and liquids. Quasicrystals, discovered in 1984, correspond to a kind of revolution in our understanding of crystallography, wherein the five-fold rotational symmetry was prohibited in long-range ordered systems. Various interesting physicochemical properties of these materials strongly depend on structural inhomogeneity at the microscopic level, and the small angle X-ray scattering method is widely used to analyze such structures. These new materials provide fundamental improvements to materials prop- erties, and are not only scientifically interesting but also industrially impor- tant for applications such as ultrafine magnetic recording media and future electronic devices. This book contains three chapters. The first chapter, written by H. Tanaka and T. Fujiwara, deals with 'Electronic Structure in Aperiodic Materials', and reviews the application of theoretical methods to determine the elec- tronic structures and resulting properties of amorphous metals, quasicrys- tals, and liquids.The second chapter, written by Y. Waseda, K. Sugiyama, and A. H. Shinohara, covers the recent topic of 'Anomalous Small Angle X- ray Scattering for Structural Inhomogeneity of Materials', starting with its fundamentals. The third chapter, 'Icosahedral Clusters in RE(TM - Al h3 1 x x Amorphous Alloys', by K. Fukamichi, A. Fujita, T. H. Chang, E. Matsubara, and Y.

It is well known that corrosion products, i.e. rust, on iron and steel surfaces cannot be assigned a typical crystallographic structure with long-range order. In fact, the structure of rust is considered to be very complicated, and some forms of rust are assigned to the amorphous state for this reason. Accurate information about the atomic-scale structure of rust is important to shed light on corrosion mechanisms of metallic materials. And, since life of steel structures is often dominated by environmental degradation or corrosion of the surface, the structure of the rust formed on iron and steel surfaces during prolonged exposure to air is of great interest. This book describes the fundamental aspects of materials characterization for the ferric oxyhydroxides formed on steel surfaces. Selected examples, from both the basic science and the applied engineering points of view, are presented. Of special interest is the new structural information on ferric oxyhydroxides containing a small amount of alloying elements. The text relates this to their various states and their role in corrosion processes. This monograph will serve as a valuable guide and source of information for specialists and non-specialists alike.

Substantial enhancement of important properties of materials is manifested when impurity concentrations are reduced to extremely low levels. Current technologies are not fully adequate and the frontiers of our present knowledge of theory and practice need exploration. New concepts and methodologies are evolving and novel purification processes are beinb developed for producing ultra-high-purity metals with purpose-designed atomic patterns for sophisticated functional applications. This book gives a critical, up-to-date evaluation starting with an extended introductory treatise on the fundamentals, followed by a detailed description of the new methods of purification of transition metals and rare earth metals, including their characterization. The subject is approached both from the basic science and applied engineering points of view.

The evolution of our understanding of most properties of new functional materials is related to our knowledge of their atomic-scale structure. To further this, several X-ray and neutron techniques are employed. The anomalous X-ray scattering (AXS) method, exploiting the so-called anomalous dispersion effect near the absorption edge of the constituent element, is one of the most powerful methods for determining the accurate partial structure functions of individual pairs of constituents or the environmental functions around specific elements in multicomponent systems. AXS is useful for both crystalline and non-crystalline systems, for studies of surface and bulk materials. This book is the first on this new method of structural characterization. It describes the basics and application principles, and also treats the specifics of application to liquid alloys, supercooled liquids, solutions, metallic glasses, oxide glasses, superconducting ionic glasses etc.

A variety of industries – information technology, aerospace, automobile, and basic and new materials manufacturing – need technological innovations, which bring high-value-added and high-quality products at low cost not only because of global competition, but also because of the perspective of en- ronmental consciousness and regulation. Thermophysical properties of hi- temperature melts are indispensable for numerical simulations of material processes such as semiconductor and optical crystal growth of the melt, and castingofsuper-high-temperaturealloysforjet-engineturbineblades,inad- tion to welding in automobile manufacturing. Recent developments in process modeling provide 3D unsteady analysis of melt convection, temperature, and heat ?ux distribution, which enables us to predict product quality. In fact, 3D process visualization using computer modeling helps us to understand complicated phenomena occurring in the melt and to control the process. Accurate data are necessary to improve the modeling, which co- e?ectively engenders high-quality products. However, crucial obstacles render measurements of thermophysical properties di?cult at elevated temperatures because of high chemical reactivity and ?uidity of melts. Substantial and persistent challenges have been made to ascertain the precise thermophysical properties of high-temperature melts. This book describes the new techniques and latest developments in the measurements of atomic structure, density, surface tension, viscosity, heat capacity, thermal and mass di?usivity, th- mal conductivity, emissivity, and electrical conductivity of high-temperature melts. In addition to up-to-date improvements in conventional techniques, some new attempts are introduced to open a new scienti?c ?eld, that is,physics of high-temperature melts.

A broad array of new engineered materials, with intricate atomic and molecular architecture for sophisticated functional applications in the computer and electronics industries, is under development. For this purpose, there is an urgent need for novel methods for precisely controlling the morphology of particulate materials. This book represents an extended introductory treatise on the fundamental aspects, new methods for the precise control of morphology (size, shape, composition, structure etc.) and accurate materials characterization, from both the basic science and the applied engineering viewpoints. This is the first major compilation of new advances covering the current status and topics related to the processing and production of precisely controlled materials. It provides a unique source of information and guidance for specialists and non-specialists alike.

In this volume we aim to introduce recent progress in the study of aperiodic materials, which include icosahedral clusters, amorphous metals, quasicrys- tals, glasses, and liquids. Quasicrystals, discovered in 1984, correspond to a kind of revolution in our understanding of crystallography, wherein the five-fold rotational symmetry was prohibited in long-range ordered systems. Various interesting physicochemical properties of these materials strongly depend on structural inhomogeneity at the microscopic level, and the small angle X-ray scattering method is widely used to analyze such structures. These new materials provide fundamental improvements to materials prop- erties, and are not only scientifically interesting but also industrially impor- tant for applications such as ultrafine magnetic recording media and future electronic devices. This book contains three chapters. The first chapter, written by H. Tanaka and T. Fujiwara, deals with 'Electronic Structure in Aperiodic Materials', and reviews the application of theoretical methods to determine the elec- tronic structures and resulting properties of amorphous metals, quasicrys- tals, and liquids.The second chapter, written by Y. Waseda, K. Sugiyama, and A. H. Shinohara, covers the recent topic of 'Anomalous Small Angle X- ray Scattering for Structural Inhomogeneity of Materials', starting with its fundamentals. The third chapter, 'Icosahedral Clusters in RE(TM - Al h3 1 x x Amorphous Alloys', by K. Fukamichi, A. Fujita, T. H. Chang, E. Matsubara, and Y.

A variety of industries – information technology, aerospace, automobile, and basic and new materials manufacturing – need technological innovations, which bring high-value-added and high-quality products at low cost not only because of global competition, but also because of the perspective of en- ronmental consciousness and regulation. Thermophysical properties of hi- temperature melts are indispensable for numerical simulations of material processes such as semiconductor and optical crystal growth of the melt, and castingofsuper-high-temperaturealloysforjet-engineturbineblades,inad- tion to welding in automobile manufacturing. Recent developments in process modeling provide 3D unsteady analysis of melt convection, temperature, and heat ?ux distribution, which enables us to predict product quality. In fact, 3D process visualization using computer modeling helps us to understand complicated phenomena occurring in the melt and to control the process. Accurate data are necessary to improve the modeling, which co- e?ectively engenders high-quality products. However, crucial obstacles render measurements of thermophysical properties di?cult at elevated temperatures because of high chemical reactivity and ?uidity of melts. Substantial and persistent challenges have been made to ascertain the precise thermophysical properties of high-temperature melts. This book describes the new techniques and latest developments in the measurements of atomic structure, density, surface tension, viscosity, heat capacity, thermal and mass di?usivity, th- mal conductivity, emissivity, and electrical conductivity of high-temperature melts. In addition to up-to-date improvements in conventional techniques, some new attempts are introduced to open a new scienti?c ?eld, that is,physics of high-temperature melts.

X-ray diffraction crystallography for powder samples is a well-established and widely used method. The book deals with fundamental properties of X-rays, geometry analysis of crystals, X-ray scattering and diffraction in polycrystalline samples and its application to the determination of the crystal structure.

It is well known that corrosion products, i.e. rust, on iron and steel surfaces cannot be assigned a typical crystallographic structure with long-range order. In fact, the structure of rust is considered to be very complicated, and some forms of rust are assigned to the amorphous state for this reason. Accurate information about the atomic-scale structure of rust is important to shed light on corrosion mechanisms of metallic materials. And, since life of steel structures is often dominated by environmental degradation or corrosion of the surface, the structure of the rust formed on iron and steel surfaces during prolonged exposure to air is of great interest. This book describes the fundamental aspects of materials characterization for the ferric oxyhydroxides formed on steel surfaces. Selected examples, from both the basic science and the applied engineering points of view, are presented. Of special interest is the new structural information on ferric oxyhydroxides containing a small amount of alloying elements. The text relates this to their various states and their role in corrosion processes. This monograph will serve as a valuable guide and source of information for specialists and non-specialists alike.

X-ray diffraction crystallography for powder samples is a well-established and widely used method. It is applied to materials characterization to reveal the atomic scale structure of various substances in a variety of states. The book deals with fundamental properties of X-rays, geometry analysis of crystals, X-ray scattering and diffraction in polycrystalline samples and its application to the determination of the crystal structure. The reciprocal lattice and integrated diffraction intensity from crystals and symmetry analysis of crystals are explained. To learn the method of X-ray diffraction crystallography well and to be able to cope with the given subject, a certain number of exercises is presented in the book to calculate specific values for typical examples. This is particularly important for beginners in X-ray diffraction crystallography. One aim of this book is to offer guidance to solving the problems of 90 typical substances. For further convenience, 100 supplementary exercises are also provided with solutions. Some essential points with basic equations are summarized in each chapter, together with some relevant physical constants and the atomic scattering factors of the elements.

Substantial enhancement of important properties of materials is manifested when impurity concentrations are reduced to extremely low levels. Current technologies are not fully adequate and the frontiers of our present knowledge of theory and practice need exploration. New concepts and methodologies are evolving and novel purification processes are beinb developed for producing ultra-high-purity metals with purpose-designed atomic patterns for sophisticated functional applications. This book gives a critical, up-to-date evaluation starting with an extended introductory treatise on the fundamentals, followed by a detailed description of the new methods of purification of transition metals and rare earth metals, including their characterization. The subject is approached both from the basic science and applied engineering points of view.

The production of multi layered thin films with sufficient reliability is a key technology for device fabrication in micro electronics. In the Co/Cu type multi layers, for example, magnetoresistance has been found as large as 80 % at 4. 2 K and 50 % at room temperature. In addition to such gigantic mag netoresistance, these multi layers indicate anti ferromagnetic and ferromag netic oscillation behavior with an increase in the thickness of the layers of the non magnetic component. These interesting properties of the new synthetic flmctional materials are attributed to their periodic and interracial structures at a microscopic level, although the origin of such peculiar features is not fully understood. Information on the surface structure or the number density of atoms in the near surface region may provide better insight. Amorphous alloys, frequently referred to as metallic glasses, are produced by rapid quenching from the melt. The second generation amorphous alloys, called "bulk amorphous alloys", have been discovered in some Pd based and Zr based alloy systems, with a super cooled liquid region at more than 120 K. In these alloy systems, one can obtain a sample thickness of several centime ters. Growing scientific and technological curiosity about the new amorphous alloys has focused on the fundamental factors, such as the atomic scale struc ture, which are responsible for the thermal stability with certain chemical compositions.

This book deals with different aspects of the structure and properties of disordered materials. Whenever the normal state of matter is affected by internal or external agencies and new states are developed, it is generally observed that the new materials possess disordered structures. However, some characteristics (such as the electronic and ionic) remain similar to those of crystalline solids. Such isotropic materials are also termed disordered solids.This book surveys the physics of materials like non transition-transition metals and alloys in their solid and liquid phases, liquid-amorphous solids and materials with super structures like fullerene lattices etc. The advancements in these materials which possess unusual physical properties provide exciting possibilities for technology and industry. Up-to-date investigations about theoretical and experimental techniques are presented here. The reviews on different materials were prepared by renowned experts in the corresponding areas.