Theory of Itinerant Electron Magnetism

Theory of Itinerant Electron Magnetism

Author: Jürgen Kübler

Publisher: Oxford University Press

ISBN: 9780191565427

Category: Science

Page: 494

View: 568

This book, in the broadest sense, is an application of quantum mechanics and statistical mechanics to the field of magnetism. Under certain well described circumstances, an immensely large number of electrons moving in the solid state of matter will collectively produce permanent magnetism. Permanent magnets are of fundamental interest, and magnetic materials are also of great practical importance as they provide a large field of technological applications. The physical details describing the many electron problem of magnetism are presented in this book on the basis of the local density functional approximation. The emphasis is on realistic magnets, for which the equations describing the many electron problem can only be solved by using computers. The great, recent and continuing improvements of computers are, to a large extent, responsible for the progress in the field. Along with a detailed introduction to the density functional theory, this book presents representative computational methods and provides the reader with a complete computer programme for the determination of the electronic structure of a magnet on a PC. A large part of the book is devoted to a detailed treatment of the connections between electronic properties and magnetism, and how they differ in the various known magnetic systems. Current trends are exposed and explained for a large class of alloys and compounds. The modern field of artificially layered systems - known as multilayers - and their industrial applications are dealt with in detail. Finally, an attempt is made to relate the rich thermodynamic properties of magnets to the ab initio results originating from the electronic structure.

Spin Fluctuation Theory of Itinerant Electron Magnetism

Spin Fluctuation Theory of Itinerant Electron Magnetism

Author: Yoshinori Takahashi

Publisher: Springer

ISBN: 9783642366666

Category: Science

Page: 181

View: 416

This volume shows how collective magnetic excitations determine most of the magnetic properties of itinerant electron magnets. Previous theories were mainly restricted to the Curie-Weiss law temperature dependence of magnetic susceptibilities. Based on the spin amplitude conservation idea including the zero-point fluctuation amplitude, this book shows that the entire temperature and magnetic field dependence of magnetization curves, even in the ground state, is determined by the effect of spin fluctuations. It also shows that the theoretical consequences are largely in agreement with many experimental observations. The readers will therefore gain a new comprehensive perspective of their unified understanding of itinerant electron magnetism.

Spin Fluctuation Theory of Itinerant Electron Magnetism

Spin Fluctuation Theory of Itinerant Electron Magnetism

Author: Yoshinori Takahashi

Publisher: Springer

ISBN: 3642366678

Category: Science

Page: 181

View: 633

This volume shows how collective magnetic excitations determine most of the magnetic properties of itinerant electron magnets. Previous theories were mainly restricted to the Curie-Weiss law temperature dependence of magnetic susceptibilities. Based on the spin amplitude conservation idea including the zero-point fluctuation amplitude, this book shows that the entire temperature and magnetic field dependence of magnetization curves, even in the ground state, is determined by the effect of spin fluctuations. It also shows that the theoretical consequences are largely in agreement with many experimental observations. The readers will therefore gain a new comprehensive perspective of their unified understanding of itinerant electron magnetism.

Theory of Itinerant Electron Magnetism

Theory of Itinerant Electron Magnetism

Author: Jürgen K. Kübler

Publisher:

ISBN: 0191915831

Category: Free electron theory of metals

Page: 0

View: 604

This second edition, in the broadest sense, is an application of quantum mechanics and statistical mechanics to the field of magnetism. It can be used for parts of a specialised course on material properties or solid-state physics and magnetism.

Spin Fluctuations in Itinerant Electron Magnetism

Spin Fluctuations in Itinerant Electron Magnetism

Author: Toru Moriya

Publisher: Springer Science & Business Media

ISBN: 9783642824999

Category: Technology & Engineering

Page: 242

View: 974

Ferromagnetism of metallic systems, especially those including transition metals, has been a controversial subject of modern science for a long time. This controversy sterns from the apparent dual character of the d-electrons responsible for magnetism in transition metals, i.e., they are itinerant elec trons described by band theory in their ground state, while at finite tem peratures they show various properties that have long been attributed to a system consisting of local magnetic moments. The most familiar example of these properties is the Curie-Weiss law of magnetic susceptibility obeyed by almost all ferromagnets above their Curie temperatures. At first the problem seemed to be centered around whether the d-elec trons themselves are localized or itinerant. This question was settled in the 1950s and early 1960s by various experimental investigations, in particular by observations of d-electron Fermi surfaces in ferromagnetic transition metals. These observations are generally consistent with the results of band calculations. Theoretical investigations since then have concentrated on explaining this dual character of d-electron systems, taking account of the effects of electron-electron correlations in the itinerant electron model. The problem in physical terms is to study the spin density fluctuati·ons, which are ne glected in the mean-field or one-electron theory, and their influence on the physical properties.

Itinerant Electron Magnetism: Fluctuation Effects

Itinerant Electron Magnetism: Fluctuation Effects

Author: Dieter Wagner

Publisher: Springer Science & Business Media

ISBN: 9789401150804

Category: Science

Page: 460

View: 922

A summary of recent developments in theoretical and experimental studies of fluctuation effects in itinerant electron magnets, focusing on novel physical phenomena: soft-mode spin fluctuations and zero-point effects, strong spin anharmonicity, magnetic frustrations in metals, fluctuation effects in Invar alloys and low-dimensional systems. All of these may be important for novel high-technology applications.

Concise Encyclopedia of Magnetic and Superconducting Materials

Concise Encyclopedia of Magnetic and Superconducting Materials

Author: K.H.J. Buschow

Publisher: Elsevier

ISBN: 0080457657

Category: Technology & Engineering

Page: 1360

View: 987

Magnetic and superconducting materials pervade every avenue of the technological world – from microelectronics and mass-data storage to medicine and heavy engineering. Both areas have experienced a recent revitalisation of interest due to the discovery of new materials, and the re-evaluation of a wide range of basic mechanisms and phenomena. This Concise Encyclopedia draws its material from the award-winning Encyclopedia of Materials and Engineering, and includes updates and revisions not available in the original set -- making it the ideal reference companion for materials scientists and engineers with an interest in magnetic and superconducting materials. * Contains in excess of 130 articles, taken from the award-winning Encyclopedia of Materials: Science and Technology, including ScienceDirect updates not available in the original set. * Each article discusses one aspect of magnetic and superconducting materials and includes photographs, line drawings and tables to aid the understanding of the topic at hand. * Cross-referencing guides readers to articles covering subjects of related interest.

先进磁性材料的模拟和检测(21世纪科技前沿丛书先进磁性材料手册第2卷)

先进磁性材料的模拟和检测(21世纪科技前沿丛书先进磁性材料手册第2卷)

Author: David J. Sellmyer

Publisher: 清华大学出版社有限公司

ISBN: 7302087016

Category: Magnetic materials

Page: 626

View: 647

本书共分四卷,每一卷集中论述一个具体的研究领域。每一章首先对该章的基本概念和重要观念进行阐述,然后从实验和理论方面进行详细地说明,最后介绍该领域的发展前景以及新的思想。

Magnetism in Condensed Matter

Magnetism in Condensed Matter

Author: Stephen Blundell

Publisher: OUP Oxford

ISBN: 9780191586644

Category: Science

Page: 272

View: 732

An understanding of the quantum mechanical nature of magnetism has led to the development of new magnetic materials which are used as permanent magnets, sensors, and information storage. Behind these practical applications lie a range of fundamental ideas, including symmetry breaking, order parameters, excitations, frustration, and reduced dimensionality. This superb new textbook presents a logical account of these ideas, staring from basic concepts in electromagnetsim and quantum mechanics. It outlines the origin of magnetic moments in atoms and how these moments can be affected by their local environment inside a crystal. The different types of interactions which can be present between magnetic moments are described. The final chapters of the book are devoted to the magnetic properties of metals, and to the complex behaviour which can occur when competing magnetic interactions are present and/or the system has a reduced dimensionality. Throughout the text, the theorectical principles are applied to real systems. There is substantial discussion of experimental techniques and current reserach topics. The book is copiously illustrated and contains detailed appendices which cover the fundamental principles.