Download or read book Structure and magnetic properties in half doped manganites Ln0 5Ca0 5MnO3 Ln written by Emanuela Pusceddu and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Le but de ce travail était de réaliser une étude systématique de la structure électronique et magnétique de la famille des manganites semi-dopés du Ca: Ln0.50Ca0.50MnO3 (Ln=REE). Nous avons focalisé notre attention sur l'ordre de charge (CO) et l'ordre orbital (OO) présents dans les manganites. Nous avons dérivé un modèle microscopique de structure nucléaire et magnétique à partir de la diffraction neutronique sur les poudres (NPD) et de calculs ab-initio afin de comparer les résultats expérimentaux et les modèles numériques et comprendre ainsi le rôle de l'inhomogénéité chimique et magnétique dans ces systèmes. La modification de l'état de spin électronique et du métal de transition par le dopage correspond à une modification structurale de la géométrie du polyèdre de coordination des atomes autour du métal de transition, induisant des changements structurels de coopération. En contraste avec l'ordre par le dopage chimique, un désordre chimique intrinsèque est associé à l'élément de dopage sur le site A du perovskite (formule générale ABO3) où sont placés les ions trivalents (RE3+) et bivalents (Ca2+). Ceci est dû à la différence de rayon ionique et d'affinité chimique entre ces ions. Afin d'étudier systématiquement l'effet de la substitution au niveau du site A et la relation entre les propriétés structurales et magnétiques, plusieurs échantillons ont été caractérisés. Les résultats de NPD sont une étape fondamentale vers la compréhension de la relation entre les propriétés structurales et magnétique et sont une source de motivation pour l'étude de la structure magnétique et des phénomènes de CO/OO par des simulations ab-initio. L'effet Jahn-Teller, les interactions de double- et super-échange, et le modèle de Zener seront introduits. Les propriétés magnétiques macroscopiques ont été mesurées en fonction de la température á l'aide d'un SQUID. La technique microscopique principale utilisée pour cette étude a été la NPD. Les instruments utilisés à l'institut Laue Langevin à Grenoble, D20 et D1A, et la méthode de Rietveld utilisée pour affiner les données expérimentales et en extraire les informations structurales seront décrits. Les résultats expérimentaux correspondant à l'étude systématique sur les échantillons de manganites de Ln0.50Ca0.50MnO3 (Ln = Pr, Nd, Tb, Dy, Ho, Tm, Yb and Lu) et une description de leur préparation seront présentés. La susceptibilité magnétique mesurée jusqu'à 530 K présente un pic large à températures élevées correspondant à la température de CO (TCO). Nous définissons la nature des corrélations magnétiques au-dessus et en-dessous de TCO dans le cadre du modèle des polarons de Zener. Nous présentons la structure nucléaire et magnétique pour tous les échantillons en fonction de la température et les déformations dues au dopage et à l'effet du rayon ionique. Tous nos systèmes ont une configuration magnétique de type pseudo-CE à la plus basse température correspondant à un état de type CE avec un effet de canting. Nous décrirons les calculs ab-initio pour modéliser notre série : le programme VASP, utilisé pour les calculs, la théorie DFT, les approximations faite, comme le fonctionnelle d'échange-corrélation (GGA-PBE), la correction d'Hubbard (GGA+U) seront présentée. Les calculs ont été effectués pour confirmer les résultats expérimentaux et pour accéder à d'autres quantités significatives comme la densité d'états électroniques. Les simulations ont été effectuées avec la DFT spin-polarisée, le GGA-PBE, et la GGA+U, pour considérer la corrélation électronique forte. Nous avons choisi deux systèmes purs: CaMnO3 et NdMnO3. Deux systèmes semi-dopés (Ln=Nd et Lu), ont été considérés, parce que les composés avec le La et le Pr ont été déjà étudié (Picozzi, Anisimov), et nous suivons la série avec Ln=Nd, et l'outre parce que le Lu, à l'instar de La, est saturé au niveau de ses orbitales 4f et qu'il présente de surcroit le plus petit rayon ionique dans la série de lanthanides.
Download or read book Bibliography written by Pierre Villars and published by Walter de Gruyter. This book was released on 2012-12-21 with total page 1827 pages. Available in PDF, EPUB and Kindle. Book excerpt: By browsing about 10 000 000 scientific articles of over 200 major journals mainly in a 'cover to cover approach' some 200 000 publications were selected. The extracted data is part of the following fundamental material research fields: crystal structures (S), phase diagrams (also called constitution) (C) and the comprehensive field of intrinsic physical properties (P). This work has been done systematically starting with the literature going back to 1900. The above mentioned research field codes (S, C, P) as well as the chemical systems investigated in each publication were included in the present work. The aim of the Inorganic Substances Bibliography is to provide researchers with a comprehensive compilation of all up to now published scientific publications on inorganic systems in only three handy volumes.
Download or read book Materials Syntheses written by Ulrich Schubert and published by Springer Science & Business Media. This book was released on 2008-11-23 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: Materials syntheses are more complex than syntheses of inorganic or organic compounds. Materials synthesis protocols often suffer from unclarities, irreproducibility, lack in detail and lack in standards. The need to change this situation is the main motivation for this book. It collects a number of detailed protocols, ranging from organic polymers to carbonaceous and ceramic materials, from gels to porous and layered materials and from powders and nanoparticles to films.
Download or read book Colossal Magnetoresistance Charge Ordering and Related Properties of Manganese Oxides written by Chintamani Nagesa Ramachandra Rao and published by World Scientific. This book was released on 1998 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal oxides constitute one of the most amazing classes of materials with a wide range of properties. They exhibit a variety of phenomena, such as ferroelectricity, ferromagnetism and superconductivity. A new aspect of metal oxides -- colossal magnetoresistance exhibited by certain manganese oxides, in particular rare earth manganates of perovskite structure -- has received much attention in the last four years. Some of these oxides show 100% magnetoresistance and have much potential for technological applications. Previously this phenomenon was found only in layered and granular metallic materials. Studies of colossal magnetoresistance have led to the discovery of many other new phenomena and properties such as charge ordering and orbital ordering. In view of the importance of colossal magnetoresistance, charge ordering and related phenomena exhibited by oxides to the physics and chemistry of solid materials, it is necessary and timely to have a book dealing with these topics. This book begins with a review of the subject followed by contributions from a number of experts which cover the present status of the subject.
Download or read book Physics of Manganites written by T.A. Kaplan and published by Springer Science & Business Media. This book was released on 1999-05-31 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: This series of books, which is published at the rate of about one per year, addresses fundamental problems in materials science. The contents cover a broad range of topics from small clusters of atoms to engineering materials and involves chemistry, physics, materials science and engineering, with length scales ranging from Ångstroms up to millimeters. The emphasis is on basic science rather than on applications. Each book focuses on a single area of current interest and brings together leading experts to give an up to date discussion of their work and the work of others. Each article contains enough references that the interested reader can access the relevant literature. Thanks are given to the Center for Fundamental Materials Research at Michigan State University for supporting this series. M. F. Thorpe, Series Editor E mail: thorpe@pa. msu. edu V PREFACE This book records invited lectures given at the workshop on Physics of Manganites, held at Michigan State University, July 26 29, 1998. Doped manganites are an interesting class of compounds that show both metal insulator and ferromagnetic to paramagnetic transitions at the same temperature. This was discovered in the early 1950s by Jonker and van Santen and basic theoretical ideas were developed by Zener (1951), Anderson and Hasegawa (1955), and deGennes (1960) to explain these transitions and related interesting observations.
Download or read book Nanomaterials written by Dieter Vollath and published by John Wiley & Sons. This book was released on 2013-09-30 with total page 403 pages. Available in PDF, EPUB and Kindle. Book excerpt: Successor of the highly acclaimed, first full-color introduction to nanomaterials - now including graphenes and carbon nanotubes This full-colored introduction to nanomaterials and nanotechnology in particular addresses the needs of engineers who need to know the special phenomena and potentials, without getting bogged down in the scientific detail of the physics and chemistry involved. Based on the author's own courses, this textbook shows how to produce nanomaterials and use them in engineering applications for novel products. Following an introduction, the text goes on to treat synthesis, characterization techniques, thermal, optical, magnetic and electronic properties, processing and, finally, emerging applications. A sound overview of the "nano world" from an application-oriented perspective. Reviews for the first edition: "The reader [of this book] profits from the broad scientific teaching experience of the author.... This book is highly recommended for everyone who wants to step onto the new and fascinating field of nanomaterials." (International Journal of Materials Research, May 2009) "The practical presentation and clarity in writing style makes this book a winner for anyone wanting to quickly learn about the fundamentals and practical side of nanomaterials." (IEEE Electrical Insulation Magazine, March/April 2009)
Download or read book Perovskites written by Richard J. D. Tilley and published by John Wiley & Sons. This book was released on 2016-03-03 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: Uniquely describes both the crystallography and properties of perovskite related materials. Practical applications in solar cells, microelectronics and telecommunications Interdisciplinary topic drawing on materials science, chemistry, physics, and geology Contains problems and answers to enhance knowledge retention
Download or read book Physics of Transition Metal Oxides written by Sadamichi Maekawa and published by Springer Science & Business Media. This book was released on 2004-06-22 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fact that magnetite (Fe304) was already known in the Greek era as a peculiar mineral is indicative of the long history of transition metal oxides as useful materials. The discovery of high-temperature superconductivity in 1986 has renewed interest in transition metal oxides. High-temperature su perconductors are all cuprates. Why is it? To answer to this question, we must understand the electronic states in the cuprates. Transition metal oxides are also familiar as magnets. They might be found stuck on the door of your kitchen refrigerator. Magnetic materials are valuable not only as magnets but as electronics materials. Manganites have received special attention recently because of their extremely large magnetoresistance, an effect so large that it is called colossal magnetoresistance (CMR). What is the difference between high-temperature superconducting cuprates and CMR manganites? Elements with incomplete d shells in the periodic table are called tran sition elements. Among them, the following eight elements with the atomic numbers from 22 to 29, i. e. , Ti, V, Cr, Mn, Fe, Co, Ni and Cu are the most im portant. These elements make compounds with oxygen and present a variety of properties. High-temperature superconductivity and CMR are examples. Most of the textbooks on magnetism discuss the magnetic properties of transition metal oxides. However, when one studies magnetism using tradi tional textbooks, one finds that the transport properties are not introduced in the initial stages.
Download or read book Transition Metal Oxides written by Chintamani Nagesa Ramachandra Rao and published by VCH Publishers. This book was released on 1995 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solid Oxide Fuel Cell Technology written by K Huang and published by Elsevier. This book was released on 2009-07-30 with total page 341 pages. Available in PDF, EPUB and Kindle. Book excerpt: High temperature solid oxide fuel cell (SOFC) technology is a promising power generation option that features high electrical efficiency and low emissions of environmentally polluting gases such as CO2, NOox and SOx. It is ideal for distributed stationary power generation applications where both high-efficiency electricity and high-quality heat are in strong demand. For the past few decades, SOFC technology has attracted intense worldwide R&D effort and, along with polymer electrolyte membrane fuel cell (PEMFC) technology, has undergone extensive commercialization development.This book presents a systematic and in-depth narrative of the technology from the perspective of fundamentals, providing comprehensive theoretical analysis and innovative characterization techniques for SOFC technology. The book initially deals with the basics and development of SOFC technology from cell materials to fundamental thermodynamics, electronic properties of solids and charged particle transport. This coverage is extended with a thorough analysis of such operational features as current flow and energy balance, and on to voltage losses and electrical efficiency. Furthermore, the book also covers the important issues of fuel cell stability and durability with chapters on performance characterization, fuel processing, and electrode poisoning. Finally, the book provides a comprehensive review for SOFC materials and fabrication techniques. A series of useful scientific appendices rounds off the book.Solid oxide fuel cell technology is a standard reference for all those researching this important field as well as those working in the power industry. - Provides a comprehensive review of solid oxide fuel cells from history and design to chemistry and materials development - Presents analysis of operational features including current flow, energy balance, voltage losses and electrical efficiency - Explores fuel cell stability and durability with specific chapters examining performance characterization, fuel processing and electrode poisoning
Download or read book Electronic Conduction in Oxides written by Nobuo Tsuda and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a revised and up-dated translation of Denki DendOsei Sankabutsu (Electronic Conduction in Oxides) published by Shokabo in Tokyo in 1983 as the second volume of the Material Science Series, which was edited for postgraduate students by T. Suzuki, S. Chikazumi, and S. Nakajima. Since the publication of the first edition, we have witnessed the historic discovery of high-Tc superconductors by J. G. Bednorz and K. A. Müller. Tbe Shokabo edition has thus been thoroughly revised to accommodate the recent developments, and K. Nasu joined as the fourth author. The constitution of the book is as follows: After a short introductory chapter, Chap. 2 is devoted 10 a brief review of transport phenomena and electronic states in oxides. It was written by Tsuda. In Chap. 3, the electron-phonon and electron electron interaction are treated theoretically by Nasu and Yanase. Nasu discusses the present status of theoretical studies of the electron-phonon interaction in solids and Yanase explains the electron correlation. Chapter 4 treats the physics ofvarious representative oxides in detail. Sections 4. 1-5 and 4. 10 were written by Tsuda and Sects. 4. 6-9 by Siratori. This chapter is intended not as an exhaustive review of the properties of each oxide, but rather as an illustration of the concepts which have developed out of the research into transport phenomena in conductive oxides. Many of these concepts are due 10 N. F. Mott. At the end of Chap.
Download or read book Nonstoichiometric Oxides written by O.T. Soerensen and published by Elsevier. This book was released on 2012-12-02 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nonstoichiometric Oxides discusses the thermodynamic and structural studies of nonstoichiometric oxides. This eight-chapter text also covers the defect-defect interactions in these compounds. The introductory chapters describe the thermodynamic properties of nonstoichiometric oxides in terms of defect complexes using the classical thermodynamic principles and from a statistical thermodynamics point of view. These chapters also include statistical thermodynamic models that indicate the ordered nonstoichiometric phase range in these oxides. The subsequent chapters examine the transport properties, such as diffusion and electrical conductivity. Diffusion theories and experimental diffusion coefficients for several systems, as well as the electrical properties of the highly defective ionic and mixed oxide conductor, are specifically tackled in these chapters. The concluding chapters present the pertinent results obtained in nonstoichiometric oxide structural studies using high-resolution electron microscopy and X-ray and neutron diffraction. Inorganic chemists and inorganic chemistry teachers and students will greatly appreciate this book.
Download or read book Functional Cobalt Oxides written by Tsuyoshi Takami and published by CRC Press. This book was released on 2014-08-04 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores why cobalt oxides have drawn interest as functional materials due to their peculiar physical properties partially originating from a rich variety of the valence and spin state of cobalt ions. The book starts with the basics of condensed matter physics and advances toward the strong electron correlation system stage. It also provi
Download or read book Intermediate Temperature Solid Oxide Fuel Cells written by Zongping Shao and published by Springer. This book was released on 2016-09-12 with total page 271 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses recent advances in intermediate-temperature solid oxide fuel cells (IT-SOFCs), focusing on material development and design, mechanism study, reaction kinetics and practical applications. It consists of five chapters presenting different types of reactions and materials employed in electrolytes, cathodes, anodes, interconnects and sealants for IT-SOFCs. It also includes two chapters highlighting new aspects of these solid oxide fuel cells and exploring their practical applications. This insightful and useful book appeals to a wide readership in various fields, including solid oxide fuel cells, electrochemistry, membranes and ceramics. Zongping Shao is a Professor at the State Key Laboratory of Materials-Oriented Chemical Engineering and the College of Energy, Nanjing University of Technology, China. Moses O. Tade is a Professor at the Department of Chemical Engineering, Curtin University, Australia.
Download or read book Sociophysics An Introduction written by Parongama Sen and published by . This book was released on 2014 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses the study and analysis of the physical aspects of social systems and models, inspired by the analogy with familiar models of physical systems and possible applications of statistical physics tools. Unlike the traditional analysis of the physics of macroscopic many-body or condensed matter systems, which is now an established and mature subject, the upsurge in the physical analysis and modelling of social systems, which are clearly many-body dynamical systems, is a recent phenomenon. Though the major developments in sociophysics have taken place only recently, the earliest attempts of proposing "Social Physics" as a discipline are more than one and a half centuries old. Various developments in the mainstream physics of condensed matter systems have inspired and induced the recent growth of sociophysical analysis and models. In spite of the tremendous efforts of many scientists in recent years, the subject is still in its infancy and major challenges are yet to be taken up. An introduction to these challenges is the main motivation for this book.
Download or read book Quantum Phase Transitions in Transverse Field Models written by Amit Dutta and published by Cambridge University Press. This book was released on 2015-01-28 with total page 357 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book establishes the fundamental connections between the physics of quantum phase transitions and the technological promise of quantum information.
Download or read book Quantum Spin Glasses Annealing and Computation written by Shu Tanaka and published by Cambridge University Press. This book was released on 2017-05-04 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum annealing is a new-generation tool of information technology, which helps in solving combinatorial optimization problems with high precision, based on the concepts of quantum statistical physics. Detailed discussion on quantum spin glasses and its application in solving combinatorial optimization problems is required for better understanding of quantum annealing concepts. Fulfilling this requirement, the book highlights recent development in quantum spin glasses including Nishimori line, replica method and quantum annealing methods along with the essential principles. Separate chapters on simulated annealing, quantum dynamics and classical spin models are provided for enhanced learning. Important topics including adiabatic quantum computers and quenching dynamics are discussed in detail. This text will be useful for students of quantum computation, quantum information, statistical physics and computer science.
