Hysteresis in Magnetism


Book Description

This book provides a comprehensive treatment of the physics of hysteresis in magnetism and of the mathematical tools used to describe it. Hysteresis in Magnetism discusses from a unified viewpoint the relationsof hysteresis to Maxwells equations, equilibrium and non-equilibrium thermodynamics, non-linear system dynamics, micromagnetics, and domain theory. These aspects are then applied to the interpretation of magnetization reversal mechanisms: coherent rotation and switching in magnetic particles, stochastic domain wall motion and the Barkhausen effect, coercivity mechanisms and magnetic viscosity, rate-dependent hysteresis and eddy-current losses. The book emphasizes the connection between basic physical ideas and phenomenological models of interest to applications, and, in particular, to the conceptual path going from Maxwells equations and thermodynamics to micromagnetics and to Preisach hysteresis modeling. - The reader will get insight into the importance and role of hysteresis in magnetism; In particular, he will learn: - which are the fingerprints of hysteresis in magnetism - which are the situations in which hysteresis may appear - how to describe mathematically these situations - how to apply these descriptions to magnetic materials - how to interpret and predict magnetic hysteresis phenomena observed experimentally




Magnetic Hysteresis


Book Description

Understanding magnetic hysteresis is vitally important to the development of the science of magnetism as a whole and to the advancement of practical magnetic device applications. Magnetic Hysteresis, by acclaimed expert Edward Della Torre, presents a clear explanation of the connection between physical principles and phenomenological hysteresis. This comprehensive book offers a lucid analysis that enables the reader to save valuable time by reducing trial-and-error design. Dr. Della Torre uses physical principles to modify Preisach modeling and to describe the complex behavior of magnetic media. While Pretsach modeling is a useful mathematical tool, its congruency and deletion properties present limitations to accurate descriptions of magnetic materials. Step-by-step, this book describes the modifications that can overcome these limitations. Special attention is given to the use of feedback around a Preisach transducer to remove the congruency restriction, and to the use of accommodation and aftereffect models to remove the deletion restriction. Magnetic state selection rules are introduced to couple scalar Preisach models to form a vector model. Magnetic Hysteresis is indispensable reading for engineers, physicists, and materials scientists who want to gain a better understanding of hysteresis losses and create more energy-efficient motor designs.




Magnetic Hysteresis in Novel Magnetic Materials


Book Description

A detailed presentation of the physics of the various hysteresis models that are currently used to explain the magnetization reversal process, including coherent and incoherent magnetization processes, micromagnetism and its application in thin films, multilayers, nanowires, particles and bulk magnets, domain wall pinning and domain wall dynamics, and Preisach modelling. Some of the faulty concepts and interpretations that still exist in the literature are rectified. Magnetic imaging techniques are reviewed, including TEM, SEM, magnetic force microscopy, and optical microscopy. Temperature, field and angular dependence of coercivity, magnetic interactions and magnetic phenomena are reviewed and their effect on magnetic hysteresis is discussed. The magnetic properties of novel materials are discussed, including nanoparticles, nanocrystalline granular solids, particulate media, thin films, and bulk magnets. Finally, present and future applications of novel materials are presented, including magnetic and magneto-optic recording media, magneto-electronics, sensors, magnetic circuit design, and novel structures created from rigid, high-energy permanent magnets.




The Science of Hysteresis: Mathematical modeling and applications


Book Description

Volume 1 covers: * Mathematical models * Differential equations * Stochastic aspects of hysteresis * Binary detection using hysteresis * Models of unemployment in economics Volume 2 covers: * Physical models of magnetic hysteresis * All aspects of magnetisation dynamics Volume 3 covers: * Hysteresis phenomena in materials * Over 2100 pages, rich with supporting illustrations, figures and equations * Contains contributions from an international list of authors, from a wide-range of disciplines * Covers all aspects of hysteresis - from differential equations, and binary detection, to models of unemployment and magnetisation dynamics.




Hysteresis in Magnetism


Book Description

Introduction: Magnetic Hysteresis. Types of Hysteresis. Maxwells Equations and Thermodynamics: Maxwells Equations in Magnetic Media. Magnetic Work and Thermodynamics. Magnetic Free Energy: Exchange and Anisotropy. Micromagnetics. Magnetic Domains and Domain Walls. The Magnetization Process: Coherent Rotation. Domain Wall Motion. Magnetization Curves. Coercivity Mechanisms. Eddy Currents. Preisach Systems: Collections of Bistable Units. Hysteresis in Preisach Systems. Appendixes: Systems of Units. Vector Relations. Reciprocity Theorems. Micromagnetic Parameters. Stochastic Processes. Bibliography. Index.




Mathematical Models of Hysteresis


Book Description

The purpose of this book is to describe in sufficient detail the mathematical models of hysteresis nonlinearities with "nonlocal memories. " The distinct feature of these nonlinearities is that their future states depend on past histories of input variations. It turns out that memories of hysteresis nonlinearities are quite selective. Indeed, experiments show that only some past input extrema (not the entire input variations) leave their marks upon future states of hysteresis nonlinearities. Thus, special mathematical tools are needed to describe nonlocal selective memories of hysteresis nonlinearities. The origin of such tools can be traced back to the landmark paper of Preisach. The book is primarily concerned with Preisach-type models of hysteresis. All these models have a common generic feature; they are constructed as superposi tions of simplest hysteresis nonlinearities-rectangular loops. The discussion is by and large centered around the following topics: various generalizations and extensions of the classical Preisach model (with special emphasis on vector generalizations), finding of necessary and sufficient conditions for the represen tation of actual hysteresis nonlinearities by various Preisach-type models, solution of identification problems for these models, and numerical implementa tion and experimental testing of Preisach-type models. Although the study of Preisach-type models constitutes the main subject of the book, some effort is also made to establish some interesting connections between these models and such topics as the critical state model for superconducting hysteresis, the classi cal Stoner-Wohlfarth model for vector magnetic hysteresis, thermal activation type models for viscosity, magnetostrictive hysteresis and neural networks.




Recent Advances in Automation, Robotics and Measuring Techniques


Book Description

This book presents the recent advances and developments in control, automation, robotics and measuring techniques. It presents contributions of top experts in the fields, focused on both theory and industrial practice. The particular chapters present a deep analysis of a specific technical problem which is in general followed by a numerical analysis and simulation and results of an implementation for the solution of a real world problem. The book presents the results of the International Conference AUTOMATION 2014 held 26 - 28 March, 2014 in Warsaw, Poland on Automation – Innovations and Future Prospectives The presented theoretical results, practical solutions and guidelines will be useful for both researchers working in the area of engineering sciences and for practitioners solving industrial problems.




Magnetism and Metallurgy of Soft Magnetic Materials


Book Description

Directed to solid-state physicists, engineers, and graduate-level students: a comprehensive treatment of the theory and application of soft magnets — vital in computer and telecommunications technology. Topics include ferromagnetism and ferrimagnetism, magnetization and domain structure, metallurgy and applications of soft magnetic materials. 227 figures.







Essentials of Paleomagnetism


Book Description

"This book by Lisa Tauxe and others is a marvelous tool for education and research in Paleomagnetism. Many students in the U.S. and around the world will welcome this publication, which was previously only available via the Internet. Professor Tauxe has performed a service for teaching and research that is utterly unique."—Neil D. Opdyke, University of Florida