Nonstoichiometry Diffusion And Electrical Conductivity In Binary Metal Oxides

The properties of materials at high temperature play a vital role in their processing and practical use. The real properties of materials at elevated temperatures are very often governed by defects in their structure. Lattice defects may consist of point defects like vacancies, interstitial atoms or substituted atoms. These classes are discussed in general and specifically for oxides, nitrides, carbides and sulfides. Defect aggregates, shear structures and adaptive structures are also described. Special attention is paid to hydrogen defects which seem to play an important role in several materials.Defects in solids lead to transport properties such as diffusion and conductivity. These themes are thoroughly treated in this book, with examples from various materials being provided. Special attention is paid to the transport properties of grain boundaries. In high temperature corrosion and other types of oxidation, the diffusion of atoms through the reaction products is often the rate limiting step of the reaction. This book takes the reader from the theoretical treatment of defects to applications in high temperature corrosion. Reactions between metals and pure oxygen lead to the formation of oxides on the surface, and the reaction rates may often be related to the diffusion coefficients of the oxide. However, in practical use alloys are subjected to other severe gaseous atmospheres which may often lead to accelerated attack on the material. The severest condition, namely where a salt deposit is combined with oxidizing gases, is called hot corrosion. This and other types of corrosion are also covered. Finally, a chapter is devoted to the prevention of corrosive attack on materials by the addition of rare earth metals.The book has been published in honour of Professor Per Kofstad on the occasion of his 60th birthday. Professor Kofstad has for many years been active in the field of high temperature chemistry in all its aspects, from basic and theoretical work to its application in high temperature corrosion of metals and alloys. The various chapters have been contributed by his friends and colleagues, all of whom are international experts in the field.

Fundamentals of Ceramics presents readers with an exceptionally clear and comprehensive introduction to ceramic science. This Second Edition updates problems and adds more worked examples, as well as adding new chapter sections on Computational Materials Science and Case Studies. The Computational Materials Science sections describe how today density functional theory and molecular dynamics calculations can shed valuable light on properties, especially ones that are not easy to measure or visualize otherwise such as surface energies, elastic constants, point defect energies, phonon modes, etc. The Case Studies sections focus more on applications, such as solid oxide fuel cells, optical fibers, alumina forming materials, ultra-strong and thin glasses, glass-ceramics, strong and tough ceramics, fiber-reinforced ceramic matrix composites, thermal barrier coatings, the space shuttle tiles, electrochemical impedance spectroscopy, two-dimensional solids, field-assisted and microwave sintering, colossal magnetoresistance, among others.

The material in this book is based on invited and contributed pa pers presented at the NATO Advanced Research Workshop on INon-stoichio l metric Compounds held in Ringberg Castle, Rottach-Egern (Bavarian Alps), Germany, July 3-9, 1988. The workshop followed previous meetings held in Mogilany, Poland (1980), Alenya, France (1982), Penn State, USA (1984) and Keele University, UK (1986). The aim of these workshops is to present and discuss up-to-date knowledge in the study of non-stoichiometry and its effect on materials properties as well as to indicate the most urgent research pathways required in this field. Since the subject of non-stoichiometry is interdisciplinary, the workshops bring together solid state physicists and chemists, surface scientists, materials scientists, ceramists and metallurgists. The present workshop, which gathered 42 scientists of an inter national reputation, mainly considered the effect of surfaces, grain boundaries and structural defects on materials properties. From discus sions during this meeting it emerged that correct understanding of properties of ceramic materials requires urgent studies on the defect structure of the interface region. Progress in this direction requires the development of the interface defect chemistry. This is the task for materials scientists in the near future. The present proceedings includes both theoretical and experimen tal work on general aspects of non-stoichiometry, defect structure and diffusion in relation to the bulk and to the interface region of such materials as high tech ceramics, solid electrolytes, electronic cera mics, nuclear materials and high Tc oxide superconductors.

The interrelation among composition, microstructure, and properties of stoichiometric and nonstoichiometric compounds is a major field of research for both scientific and technological reasons. As such, this book focuses on metal oxides, which present a large diversity of electrical, magnetic, optical, optoelectronic, thermal, electrochemical, and catalytic properties, making them suitable for a wide range of applications. By bringing together scientific contributions with special emphasis on the interrelations between materials chemistry, processing, microstructures, and properties of stoichiometric and nonstoichiometric metal oxides, this book highlights the importance of tightly integrating high-throughput experiments (including both synthesis and characterization) and efficient and robust theory for the design of advanced materials.

Die langerwartete Komplettierung der Reihe 'Inorganic Reactions and Methods' beginnt jetzt mit der Publikation des 6. Bandes. Seit Jahren vielfach in Forschung und Berufsalltag bewährt, behandelt die Reihe alle Gebiete der anorganischen Synthesechemie - die Chemie der Elemente, Koordinationsverbindungen, Donor-Acceptor-Addukte, organometallische Stoffe, Polymere und Festkörper sowie bioanorganische Materialien. Mit Autoren-, Sach- und Verbindungsregister! (07/98)

The expected end of the “oil age” will lead to increasing focus and reliance on alternative energy conversion devices, among which fuel cells have the potential to play an important role. Not only can phosphoric acid and solid oxide fuel cells already efficiently convert today’s fossil fuels, including methane, into electricity, but other types of fuel cells, such as polymer electrolyte membrane fuel cells, have the potential to become the cornerstones of a possible future hydrogen economy. Featuring 21 peer-reviewed entries from the Encyclopedia of Sustainability Science and Technology, Fuel Cells offers concise yet comprehensive coverage of the current state of research and identifies key areas for future investigation. Internationally renowned specialists provide authoritative introductions to a wide variety of fuel cell types, and discuss materials, components, and systems for these technologies. The entries also cover sustainability and marketing considerations, including comparisons of fuel cells with alternative technologies.