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Magnetic Order and Coupling Phenomena

Author : Christian Schubert

Publisher : Springer

Page : 136 pages

File Size : 17,15 MB

Release : 2014-06-03

Category : Science

ISBN : 3319071068

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Book Description

This thesis presents recent developments in magnetic coupling phenomena of ferrimagnetic rare-earth transition-metal Tb-Fe alloys and coupled systems consisting of ferri-/ferromagnetic heterostructures. Taking advantage of the tunability of the exchange coupling between ferrimagnetic and ferromagnetic layers by means of stoichiometry of the Tb-Fe layer, the variable number of repetitions in the Co/Pt multilayer as well as the thickness of an interlayer spacer, it is demonstrated that large perpendicular unidirectional anisotropy can be induced at room temperature. This robust perpendicular exchange bias at room temperature opens up a path towards applications in spintronics.



Nonlinear Phenomena And Chaos In Magnetic Materials

Author : Philip E Wigen

Publisher : World Scientific

Page : 262 pages

File Size : 41,3 MB

Release : 1994-05-06

Category : Technology & Engineering

ISBN : 9814505498

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Book Description

In this book, some of the principal investigators of the phenomena have reviewed their successes. The contributions include an overview of the field by H Suhl, followed by a detailed review of the high-power response of magnetic materials. Following that chapter, a number of authors review the phenomena for a variety of magnetic materials and pumping configurations.In the final chapter, evidence of another nonlinear effect is reviewed. Using a pulsed driving field, it is possible to excite a travelling spin wave. The nonlinear contributions will give rise to a “bunching” effect which compensates for the dispersive effects to produce a shape-preserving traveling wave pulse known as solitons.Ordered magnetic materials have provided a rich source for the investigation of nonlinear phenomena. These investigations have contributed much to our knowledge of the behavior of chaotic systems, as well as to a better understanding of the high-power response of the magnetic materials themselves.



Magnetoelectric Interaction Phenomena in Crystals

Author : Manfred Fiebig

Publisher : Springer Science & Business Media

Page : 342 pages

File Size : 50,27 MB

Release : 2013-11-09

Category : Science

ISBN : 1402027079

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Book Description

In the quest for higher data density in information technology manipulation of magnetization by other means than magnetic fields has become an important challenge. This lead to a startling revival of the magnetoelectric effect, which characterizes induction of a polarization by a magnetic field or of a magnetization by an electric field. The magnetoelectric crosslink of material properties opens just those degrees of freedom which are needed for the mutual control of magnetic and electric states. The book gives a state-of-the-art review on magnetoelectrics research, classifies current research tendencies, and points out possible future trends. Novel compounds and growth techniques and new theoretical concepts for the understanding of magnetoelectric coupling phenomena are introduced. Highlights are the discovery of "gigantic" magnetoelectric effects which are strong enough to trigger electric or magnetic phase transitions; the concept of magnetochirality; and development "structural" magnetoelectric effects in artificial multiphase compounds. The book is addressed to condensed-matter physicists with a particular focus on experts in highly correlated systems.



Magnetism and Transport Phenomena in Spin-Charge Coupled Systems on Frustrated Lattices

Author : Hiroaki Ishizuka

Publisher : Springer

Page : 142 pages

File Size : 21,6 MB

Release : 2015-07-13

Category : Technology & Engineering

ISBN : 443155663X

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Book Description

In this thesis, magnetism and transport phenomena in spin-charge coupled systems on frustrated lattices are theoretically investigated, focusing on Ising-spin Kondo lattice models and using a combination of Monte Carlo simulation and other techniques such as variational calculations and perturbation theory. The emphasis of the study is on how the cooperation of spin-charge coupling and geometrical frustration affects the thermodynamic properties of the Kondo lattice models; it presents the emergence of various novel magnetic states, such as the partial disorder, loop-liquid, and spin-cluster states. The thesis also reveals that the magnetic and electronic states and transport properties of these models demonstrate peculiar features, such as Dirac half-metals, anomalous Hall insulators, and spin Hall effects. Study of novel magnetic states and exotic transport phenomena in Kondo lattice systems is a field experiencing rapid progress. The interplay of charge and spin degrees of freedom potentially gives rise to various novel phases and transport phenomena which are related to strongly correlated electrons, frustrated magnetism, and topological states of matter. The results presented in this thesis include numerical calculations that are free from approximations. Accordingly, they provide reliable reference values, both for studying magnetism and transports of related models and for experimentally exploring novel states of matter in metallic magnets.



Handbook of Magnetic Phenomena

Author : Harry E. Burke

Publisher : Springer Science & Business Media

Page : 560 pages

File Size : 48,71 MB

Release : 2012-12-06

Category : Science

ISBN : 9401170061

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Book Description

The general theory of magnetism and the vast range of individual phe nomena it embraces have already been examined in many volumes. Spe cialists hardly need help in charting their way through the maze of pub lished information. At the same time, a nonspecialist might easily be discouraged by this abundance. Most texts are restricted in their coverage, and their concepts may well appear to be disorganized when the uninitiated attempt to consider them in their totality. Since the subject is already thoroughly researched with very little new information added year by year, this is hardly a satisfactory state of affairs. By now, it should be possible for anyone with even a minimum of technical competence to feel com pletely at home with all of the basic magnetic principles. The present volume addresses this issue by stressing simplicity-sim plicity of order and simplicity of range as well as simplicity of detail. It proposes a pattern of logical classification based on the electronic con sequences that result whenever any form of matter interacts with any kind of energy. An attempt has been made to present each phenomenon of interest in its most visually graphic form while reducing the verbal de scription to the minimum needed to back up the illustrations. This might be called a Life magazine type of approach, in which each point is prin cipally supported by a picture. The illustrations make use of two (perhaps unique) conventions.



Magnetic Exchange Phenomena in Reduced Dimensions Studied by Neutron Scattering

Author : Thomas Saerbeck

Publisher :

Page : 207 pages

File Size : 39,89 MB

Release : 2012

Category :

ISBN :

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Book Description

[Truncated abstract] This thesis deals with magnetic exchange interactions in thin lm magnetic materials focusing on phenomena related to intrinsic parameters of magnetic, structural and chemical order. In particular, the investigation is of two magnetic thin film systems, a Cu0.94Mn0.06/Co multilayer displaying a temperature-dependent magnetic ordering due to exchange coupling originating from dilute paramagnetic Mn spins, and thin films of chemical order modulated FePt3, showing a unique self-exchange bias effect. Detailed real-space models of the magnetic structure are obtained using polarized neutron reffectometry and high-angle neutron diffraction, speciffcally chosen to probe interface and bulk magnetic characteristics, respectively, in connection with complementary structural and magnetic characterization tools. It will be discussed, how the random distribution of dilute magnetic impurity centers in the Cu0.94Mn0.06/Co multilayers leads to a temperature-dependent interlayer exchange coupling with a strong biquadratic component. This manifests in an in-plane magnetic domain structure with a canted magnetization, i.e. a deviation from collinear alignments of external magnetic field and magnetization. The domain magnetizations show a high degree of vertical correlation in the form of columns throughout the multilayer, in which the sense of canting alternates in sign for each subsequent magnetic layer. Detailed analysis of temperature and field dependences of the magnetic structure lead to fundamental exchange energies, which are utilized in constructing a phenomenological model of exchange interactions between dilute magnetic impurities and the ferromagnetic layers. In addition to this, the second study deals with the effect of chemical order of the constituent atoms in the alloy FePt3 on the magnetic order on atomic and sub-micrometer scales. Depending on the long-range chemical order, ferromagnetic or antiferromagnetic grains exist below the respective transition temperatures. As such, the system constitutes a new way of controlling the magnetic composition of thin lms without changing the materials composition, stoichiometry or lattice structure. The interfacing of the two magnetic grains leads to the observation of a unique self-exchange bias effect. Based on studies in thin films of FePt3 with varying degree of chemical order and the evolution of exchange bias with respect to interface and volume of the chemically ordered grains, a mono-stoichiometric FePt3 ferromagnetic/antiferromagnetic multilayer is presented. Analysis of the magnetic structure in the arti cially layered thin film elucidates the magnetic composition and origin of the observed exchange bias. Due to the unique mono-stoichiometric structure, the system opens possibilities to study magnetic phenomena in perfect lattice-matched systems...



Superconductivity

Author : Charles P. Poole

Publisher : Elsevier

Page : 671 pages

File Size : 40,85 MB

Release : 2010-07-20

Category : Science

ISBN : 0080550487

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Book Description

Superconductivity, 2E is an encyclopedic treatment of all aspects of the subject, from classic materials to fullerenes. Emphasis is on balanced coverage, with a comprehensive reference list and significant graphicsfrom all areas of the published literature. Widely used theoretical approaches are explained in detail. Topics of special interest include high temperature superconductors, spectroscopy, critical states, transport properties, and tunneling.This book covers the whole field of superconductivity from both the theoretical and the experimental point of view. Comprehensive coverage of the field of superconductivity Very up-to date on magnetic properties, fluxons, anisotropies, etc. Over 2500 references to the literature Long lists of data on the various types of superconductors



Physical Phenomena At High Magnetic Fields Ii

Author : John Robert Schrieffer

Publisher : World Scientific

Page : 810 pages

File Size : 10,43 MB

Release : 1996-05-25

Category :

ISBN : 9814548499

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Book Description

The purpose of the conference was to bring together experts in research areas of science in which high magnetic fields play an important role, to critically assess the current status of research in these areas, and to discuss promising new directions in science, as well as applications which are at the forefront of these fields.The program consisted of talks given by leading experts presenting overviews and critical assessments of certain areas, including semiconductors, the quantum Hall effect, heavy fermions, superconductivity, organic solids, chemical systems, and the generation and use of high magnetic fields in basic and applied research.



Molecular Magnets

Author : Juan Bartolomé

Publisher : Springer Science & Business Media

Page : 401 pages

File Size : 32,21 MB

Release : 2013-10-17

Category : Science

ISBN : 3642406092

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Book Description

This book provides an overview of the physical phenomena discovered in magnetic molecular materials over the last 20 years. It is written by leading scientists having made the most important contributions to this active area of research. The main topics of this book are the principles of quantum tunneling and quantum coherence of single-molecule magnets (SMMs), phenomena which go beyond the physics of individual molecules, such as the collective behavior of arrays of SMMs, the physics of one-dimensional single–chain magnets and magnetism of SMMs grafted on substrates. The potential applications of these physical phenomena to classical and quantum information, communication technologies, and the emerging fields of molecular spintronics and magnetic refrigeration are stressed. The book is written for graduate students, researchers and non-experts in this field of research.



Physical Phenomena At High Magnetic Fields - Iv

Author : Gregory S Boebinger

Publisher : World Scientific

Page : 542 pages

File Size : 30,93 MB

Release : 2002-07-01

Category : Science

ISBN : 9814488968

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Book Description

Physical Phenomena at High Magnetic Fields IV (PPHMF-IV) was the fourth in the series of conferences sponsored by the National High Magnetic Field Laboratory (NHMFL). The success of PPHMF-I, II and III, held in 1991, 1995 and 1998 respectively, encouraged the organizers to once again bring together experts in scientific research areas where high magnetic fields play an important role, to critically assess the current status of research in these areas, and to discuss promising new directions in science, as well as applications which are in the forefront of these fields.