Surface Segregation in Multicomponent Systems


Book Description

The study of surface segregation, although of great technological importance, has been largely restricted to experimental work due to limitations associated with theoretical methods. However, recent improvements in both first-particle and semi-empirical methods are opening, the doors to an array of new possibilities for surface scientists. We apply one of these techniques, the Bozzolo, Ferrante and Smith (BFS) method for alloys, which is particularly suitable for complex systems, to several aspects of the computational modeling of surfaces and segregation, including alloy surface segregation, structure and composition of alloy surfaces, and the formation of surface alloys. We conclude with the study of complex NiAl-based binary, ternary and quaternary thin films (with Ti, Cr and Cu additions to NiAl). Differences and similarities between bulk and surface compositions are discussed, illustrated by the results of Monte Carlo simulations. For some binary and ternary cases, the theoretical predictions are compared to experimental results, highlighting the accuracy and value of this developing theoretical tool.Bozzolo, Guillermo and Ferrante, John and Noebe, Ronald D. and Good, Brian and Honecy, Frank S. and Abel, PhillipGlenn Research CenterMETAL SURFACES; THIN FILMS; SURFACE STABILITY; ALLOYS; SEPARATION; MONTE CARLO METHOD; NICKEL ALUMINIDES




Surface Segregationphenomena


Book Description

The purpose of this book is to discuss the phenomena associated with the segregation of one element in a multicomponent material. It describes the kinetics of segregation and contains a tabular summary of the pros and cons of the various models. The easy-to-read chapters outline in detail the macroscopic approach and provide an in-depth review of broken-bond models. This comprehensive informative resource also addresses important multicomponent systems. These systems include metals with non-metallic constituents, semiconductor-metal interfaces, steels and steel-related alloys, and real catalysts. Readers of this text will gain a good fundamental understanding and overview of surface, interfacial, and selvedge segregation. Those who have an interest in physics, vacuum science, material science, and chemical, mechanical, and electrical engineering will benefit from this imperative work.




Surface Segregation


Book Description

The book presents the fundamental aspects of surface segregation theory. The material is presented in a self-contained manner and mathematical procedures are worked through in some cases in order to provide the reader with the necessary opportunity to realize the restrictions under which the expressions are valid.




Surface Alloys and Alloy Surfaces


Book Description

DescriptionSurface Alloys and Alloy Surfaces is concerned with the structural, compositional, electronic and chemical properties of the surfaces of solids in which the surface layers, at least are alloyed. Two different categories of system are covered - the surfaces of bulk alloys (alloy surfaces) and surface phases in which one or more outermost atomic layers are alloyed, while the underlying bulk involves no such intermixing (surface alloys).Importance of TopicThe surfaces of bulk alloys have long been known to be of practical interest for their chemical properties. It has also long been known that the surface composition of such alloys commonly differs from that of the underlying bulk. However, our understanding of these chemical and physical phenomena is far from complete and the application of surface science methods to investigate these phenomena is a manifestation of a general trend to study the surfaces of increasing complexity. Surface alloy formation, as a much more recently recognized phenomenon deserves more attention.Why This TitleThis title is important as it provides new insights into a mixture of new and old problems. It is the first to cover the important mixture of material on surface alloys and alloy surfaces. Each chapter is written by experts in different areas of these two interrelated topics, covering theory and experiment, physics and chemistry, geometrical and electronic structure. The coverage of the surface alloy topic is especially novel as it is relatively newly-recognised as quite a common phenomenon.




Separation of Multiphase, Multicomponent Systems


Book Description

This highly detailed reference represents an elaborate development of the theory of processing oil and natural gas and its application in the field -- indispensable for graduate engineering students and professionals alike. The renowned expert author, a professor at Moscow State University, has ample experience in both lecturing and publishing, albeit in the Russian language. This book is thus the first to provide a translation compiling his extensive knowledge, much of which remained unpublished due to security restrictions in the former Soviet Union. Based upon and compiled from Professor Sinaiski's university lectures, the first chapters treat the technical facilities for preparing and processing natural hydrocarbon substances. The following systematic approach go on to explain the behaviors of fluids, gases and droplets separately for solutions, suspensions and emulsions, as well as for gas-liquid mixtures. The resulting work is of interest both for senior students as well as for engineers working in this field.




Practical Guide to Surface Science and Spectroscopy


Book Description

Practical Guide to Surface Science and Spectroscopy provides a practical introduction to surface science as well as describes the basic analytical techniques that researchers use to understand what occurs at the surfaces of materials and at their interfaces. These techniques include auger electron spectroscopy, photoelectron spectroscopy, inelastic scattering of electrons and ions, low energy electron diffraction, scanning probe microscopy, and interfacial segregation. Understanding the behavior of materials at their surfaces is essential for materials scientists and engineers as they design and fabricate microelectronics and semiconductor devices. The book gives over 100 examples, discussion questions and problems with varying levels of difficulty. Included with this book is a CD-ROM, which not only contains the same information, but also provides many elements of animation and interaction that are not easily emulated on paper. In diverse subject matters ranging from the operation of ion pumps, computer-assisted data acquisition to tapping mode atomic force microscopy, the interactive component is especially helpful in conveying difficult concepts and retention of important information. The succinct style and organization of this practical guide is ideal for anyone who wants to get up to speed on a given topic in surface spectroscopy or phenomenon within a reasonable amount of time. - Both theory and practice are emphasized - Logical organization allows one to get up to speed on any given topic quickly - Numerous examples, questions for discussion and practice problems are included - The CD includes animation and interactive elements that help to convey difficult concepts




Atomistics of Fracture


Book Description

It is now more than 100 years since certain detrimental effects on the ductility of iron were first associated with the presence of hydrogen. Not only is hydrogen embrittlement still a major industri al problem, but it is safe to say that in a mechanistic sense we still do not know what hydrogen (but not nitrogen or oxygen, for example) does on an atomic scale to induce this degradation. The same applies to other examples of environmentally-induced fracture: what is it about the ubiquitous chloride ion that induces premature catastrophic fracture (stress corrosion cracking) of ordinarily ductile austenitic stainless steels? Why, moreover, are halide ions troublesome but the nitrate or sulfate anions not deleterious to such stainless steels? Likewise, why are some solid metals embrit tled catastrophically by same liquid metals (liquid metal embrit tlement) - copper and aluminum, for example, are embrittled by liquid mercury. In short, despite all that we may know about the materials science and mechanics of fracture on a macroscopic scale, we know little about the atomistics of fracture in the absence of environmental interactions and even less when embrittlement phe nomena such as those described above are involved. On the other hand, it is interesting to note that physical chemists and surface chemists also have interests in the same kinds of interactions that occur on an atomic scale when metals such as nickel or platinum are used, for example, as catalysts for chemical reactions.




Apparent and Microscopic Contact Angles


Book Description

This book chronicles the proceedings of the International Symposium on Apparent and Microscopic Contact Angles, held in conjunction with the American Chemical Society meeting in Boston, August 24--27, 1998. The symposium provided an opportunity to discuss several controversial issues associated with interfacial phenomena that govern the behavior of




Trends in Biomaterials Research


Book Description

Biomaterials serve as synthetic or natural materials used to replace parts of living systems or to enhance contact with living tissue. Biomaterials are intended to interface with biological systems to evaluate, treat, augment or replace any tissue, organ or function of the body. A biomaterial is different from a biological material such as bone that is produced by a biological system. Artificial hips, vascular stents, artificial peacemakers, and catheters are all made from different biomaterials and comprise different medical devices. This book presents new approaches to biomaterial development including multi-field bone remodeling, novel strategies for conferring antibacterial properties to bone cement, polyacrylonitrile-based biomaterials for enzyme immobilisation and functionalised magnetic nanoparticles for tissue engineering.