Electronically Highly Correlated Ternary Transition Metal Oxides

Introduction: Transition metal oxides represent a large class of compounds with a uniquely wide range of electronic properties. Some of these properties, like the magnetism of loadstone, have been known since antiquity. Others, like high-temperature superconductivity have been discovered only recently and indeed would have been thought of being impossible 20 years ago. Transition metal oxides may be good insulators, semiconductors, metals or superconductors. Many of them display a metal-to-insulator transition (MIT) as a function of an external control parameter (usually temperature, pressure or chemical composition). The differences of electrical conductivity are also reflected by drastic changes of other physical properties related to the electronic structure. The electrical, magnetic and optical properties of transition metal oxides find a rich field of important technical applications. A classical example is the wide use of ferrites in electronic devices. Further examples of suitable technological applications include wide gap semiconductors, superconductors and thermoelectric materials, to mention just a few. Apart from these exciting electronic properties, some transition metal oxides exhibit a remarkable mechanical and high-temperature stability together with a strong resistance against corrosion, thus forming ideal coating materials. Several transition metal oxides may also serve as catalysts. It was the discovery of high-temperature superconductivity in the cuprates and, subsequently, of the colossal magneto-resistance effect (CMR) in the manganates that triggered a tremendous research effort in transition metal oxides during the last decade. [...]

Extensive studies of high-Tc cuprate superconductors have stimualted investigations into various transition-metal oxides. Mott transitions in particular provide fascinating problems and new concepts in condensed matter physics. This book is a collection of overviews by well-known, active researchers in this field. It deals with the latest developments, with particular emphasis on the theoretical, spectroscopic, and transport aspects.

Transition metal oxides form a series of compounds with a uniquely wide range of electronic properties. They have important applications as dielectrics, semiconductors, and metals, and as materials for magnetic and optical uses. The recent discovery of high-temperature superconductors has brought the attention of a wide scientific community to this area, and has highlighted the problems involved in trying to understand transition metal oxides. The present book is not primarily about high Tc superconductors, although their properties are discussed in the final section. The main aim is to describe the varied electronic behavior shown by transition metal oxides, and to discuss the different types of theoretical models that have been proposed to interpret it. It is intended to provide an introduction to this fascinating and complex field, at a level suitable for graduate students and other research workers with a background in solid-state chemistry or physics.

I Theory of Mott Transition and Correlated Metals.- Classification Scheme of the Metal-Insulator Transition and Anomalous Metals.- The Mott Transition: Results from Mean-Field Theory.- Some Aspects of Spin Gap in One- and Two-Dimensional Systems.- Quasi-Particles in Two-Dimensional Hubbard Model: Splitting of Spectral Weight.- Almost Localized Fermions and Mott-Hubbard Transitions at Non-Zero Temperature.- Anomalous Physical Properties Around Magnetic and Metal-Insulator Transitions - A Spin-Fluctuation Theory.- Exact Diagonalization Study of Strongly Correlated Electron Models: Hole Pockets and Shadow Bands in the Doped t - J Model.- II Electronic Structure.- Electronic Band Structures of LaMO3 (M = Ti, V, Cr, ..., Ni, Cu) in the Local Spin-Density Approximation.- First-Principles Calculations of the Electronic Structure and Spectra of Strongly Correlated Systems: LDA + U Method.- Unrestricted Hartree-Fock Study of Perovskite-iype Transition-Metal Oxides.- Electronic Structure of Transition Metal Compounds.- Core-Level Spectroscopy in Early-Transition-Metal Compounds.- Systematics of Optical Gaps in Perovskite-iype 3d Transition Metal Oxides.- III Charge Transport and Excitations.- Optical Spectroscopy on the Mott Transition in Perovskiteiype Titanates.- Spectral Weight Transfer and Mass Renormalization in Correlated d-Electron Systems.- Charge Transport Properties of Strongly Correlated Metals near Charge Transfer Insulator to Metal Transition.- Infrared Studies of Kondo Insulator and Related Compounds.- IV Magnetic Response.- Magnetic Correlations in Doped Transition-Metal Oxides.- Spin and Charge Differentiation in Doped CuO2 Planes Observed by Cu NMR/NQR Spectra.- Orbital-Spin Coupling in V2O3 and Related Oxides.- Magnetic and Transport Properties of the Kondo Lattice Model with Ferromagnetic Exchange Coupling.- V New Materials.- Superconductivity, Magnetism and Metal-Insulator Transitions in Some Ternary and Pseudoternary 3d-, 4d-, and 5d-Metal Oxides.- NMR Studies of Superconductivity and Metal-Insulator Transition in Cu Spinel CuM2X4 (M = Rh, Ir and X = S, Se).- Index of Contributors.

This book details the application of the OLCAO method for calculating the properties of solids from fundamental principles to a wide array of material systems. The method specializes in large and complex models and is able to compute a variety of useful properties including electronic, optical, and spectroscopic properties.

Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Industrial and academic scientists face increasing challenges to find cost-effective and environmentally sound methods for converting natural resources into fuels, chemicals and energy. With over 7000 papers published in this field of catalysis each year, keeping up with the literature can be difficult. Catalysis Volume 27 presents critical and comprehensive reviews of the hottest literature published over the last twelve months. Covering major areas such as chemical transformations using two-dimensional hybrid nanocatalysts, conversion of biomass-derived syngas to fuels and catalytic oxidation of organic pollutants in aqueous solution using sulfate radicals, this book is a useful reference for anyone working in catalysis and an essential resource for any library.