Theory of Spin Wave Excitations in Ferromagnetic Films PDF Download

Author: R. C. Moul
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author:
Publisher: Elsevier
ISBN: 044459826X
Category : Science
Languages : en
Pages : 512

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Book Description
Modern Problems in Condensed Matter Sciences, Volume 22.2: Spin Waves and Magnetic Excitations focuses on the processes, methodologies, reactions, principles, and approaches involved in spin waves and magnetic excitations, including magnetic systems, fluctuations, resonance, and spin dynamics. The selection first elaborates on spin-wave resonance in metals, excitations in low-dimensional magnetic systems, and the theory of magnetic excitations in disordered systems. Topics include spin waves in ferromagnets with weak fluctuations of the exchange interaction; dynamics of propagating excitations; models of two-dimensional magnetic systems; spin-wave resonance in bulk metals; and standing spin-wave resonance in thin films. The manuscript then ponders on spin dynamics of amorphous magnets and magnetic excitations in spin glasses, including dynamics in reentrant spin glasses, dynamics of classical spin glasses, spin dynamical theory, spin dynamics of locally isotropic materials, and effects of dilution. The book takes a look at nuclear spin and magnetoelastic excitations and magnetic impuritons in antiferromagnetic dielectric crystals. Discussions focus on coherent and incoherent impurity excitations, equations of motion and the energy of a magnetoelastic medium, magnetoelastic excitations near magnetic orientational phase transitions, and the effect of frequency pulling on the behavior of nuclear spin echo signals. The selection is a vital source of data for researchers interested in spin waves and magnetic excitations.

Author: M G Cottam
Publisher: World Scientific
ISBN: 981450548X
Category : Technology & Engineering
Languages : en
Pages : 475

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In the past few years, there has been a rapidly growing interest in the properties of spin waves (or magnons) in ordered magnetic materials. These are the low-lying excitations that characterize the dynamical behavior of the magnetization variables in ferromagnets, ferrimagnets and antiferromagnets, particularly at low temperatures. Many of the recent developments concerning spin waves have been directed towards understanding their behavior in limited magnetic samples. At the same time, there have been dramatic advances in the experimental techniques, both for preparing high-quality magnetic samples in the form of thin films and superlattices and for the study of the spin-wave excitations themselves. Magnetic thin films have long been of technological as well as scientific interest and an understanding of both the linear and nonlinear aspects of their magnetic behavior is important.

Author: Daniel D. Stancil
Publisher: Springer Science & Business Media
ISBN: 0387778659
Category : Technology & Engineering
Languages : en
Pages : 348

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This book begins by introducing magnetism and discusses magnetic properties of materials, magnetic moments of atoms and ions, and the elements important to magnetism. It covers magnetic susceptibilities and electromagnetic waves in anisotropic dispersive media among other topics. There are problems at the end of each chapter, many of which serve to expand or explain the material in the text. The bibliographies for each chapter give an entry to the research literature.

Author: Korbinian Perzlmaier
Publisher:
ISBN: 9783832519049
Category :
Languages : en
Pages : 0

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This thesis deals with the propagation of spin waves in thin Ni80Fe20 films. Its specific aims are to experimentally determine a dispersion relation for propagating spin waves in thin ferromagnetic films, and to determine phase velocities, group velocities and damping. Additonally, an analytic dispersion relation based upon the linearized Landau-Lifshitz-Gilbert (LLG) equation is derived, from which the experimental findings can be reproduced using a theoretical model. Further on, this thesis reports on the direct observation of the interference of spin waves. This thesis is structured as follows: After an introduction in chapter 1, the basic principles of magnetostatics are sketched in chapter 2, followed by the principles of magnetodynamics in chapter 3. Based upon these principles, in chapter 4 a theory for the propagation of spin waves in ferromagnetic thin films is developed. The experimental part of this thesis begins with an overview of the experimental setup for Time Resolved Scanning Kerr Microscopy (TRSKEM) in chapter 5, and continues with the results of spin wave propagation and interference in chapter 6. The experimental results are compared to the theoretical predictions of the model developed in chapter 4. Chapter 7 gives a summary of the results and an outlook towards possible future developments. The appendix gives additional information on experimental and theoretical details.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 12

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We develop the theory of exchange/dipole spin wave excitations of ferromagnetic nanowires of cylindrical cross section, where the magnetization is parallel to the axis of the wire. In addition, we provide the theory of the microwave response of such structures, for the case where the nanowire is also a conductor. We present explicit calculations of both the mode structure of nanowires, and also their ferromagnetic resonance spectrum, with attention to recent experimental studies. We compare differences between the physical picture appropriate for the cylinder, with the well studied case of the ferromagnetic film.

Author: Daniel D. Stancil
Publisher: Springer Nature
ISBN: 3030685829
Category : Science
Languages : en
Pages : 252

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This book presents a collection of problems in spin wave excitations with their detailed solutions. Each chapter briefly introduces the important concepts, encouraging the reader to further explore the physics of spin wave excitations and the engineering of spin wave devices by working through the accompanying problem sets. The initial chapters cover the fundamental aspects of magnetization, with its origins in quantum mechanics, followed by chapters on spin wave excitations, such as the magnetostatic approximation, Walker's equation, the spin wave manifold in the three different excitation geometries of forward volume, backward volume and surface waves, and the dispersion of spin waves. The latter chapters focus on the practical aspects of spin waves and spin wave optical devices and use the problem sets to introduce concepts such as variational analysis and coupled mode theory. Finally, for the more advanced reader, the book covers nonlinear interactions and topics such as spin wave quantization, spin torque excitations, and the inverse Doppler effect. The topics range in difficulty from elementary to advanced. All problems are solved in detail and the reader is encouraged to develop an understanding of spin wave excitations and spin wave devices while also strengthening their mathematical, analytical, and numerical programming skills.

Author: Dimosthenis Kontos
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author: Michael Coey
Publisher: Springer
ISBN: 9783030632083
Category : Science
Languages : en
Pages : 1679

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Book Description
This handbook presents a comprehensive survey of magnetism and magnetic materials. The dramatic advances in information technology and electromagnetic engineering make it necessary to systematically review the approved key knowledge and summarize the state of the art in this vast field within one seminal reference work. The book thus delivers up-to-date and well-structured information on a wealth of topics encompassing all fundamental aspects of the underlying physics and materials science, as well as advanced experimental methodology and applications. It features coverage of the host of fascinating and complex phenomena that arise from the use of magnetic fields in e.g. chemistry and biology. Edited by two internationally renowned scholars and featuring authored chapters from leading experts in the field, Springer’s Handbook of Magnetism and Magnetic Materials is an invaluable source of essential reference information for a broad audience of students, researchers, and magnetism professionals.

Author: Ulrich Köbler
Publisher: Springer Science & Business Media
ISBN: 3642024882
Category : Technology & Engineering
Languages : en
Pages : 402

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Spin wave theory of magnetism and BCS theory of superconductivity are typical theories of the time before renormalization group (RG) theory. The two theories consider atomistic interactions only and ignore the energy degrees of freedom of the continuous (infinite) solid. Since the pioneering work of Kenneth G. Wilson (Nobel Prize of physics in 1982) we know that the continuous solid is characterized by a particular symmetry: invariance with respect to transformations of the length scale. Associated with this symmetry are particular field particles with characteristic excitation spectra. In diamagnetic solids these are the well known Debye bosons. This book reviews experimental work on solid state physics of the last five decades and shows in a phenomenological way that the dynamics of ordered magnets and conventional superconductors is controlled by the field particles of the infinite solid and not by magnons and Cooper pairs, respectively. In the case of ordered magnets the relevant field particles are called GSW bosons after Goldstone, Salam and Weinberg and in the case of superconductors the relevant field particles are called SC bosons. One can imagine these bosons as magnetic density waves or charge density waves, respectively. Crossover from atomistic exchange interactions to the excitations of the infinite solid occurs because the GSW bosons have generally lower excitation energies than the atomistic magnons. According to the principle of relevance the dynamics is governed by the excitations with the lowest energy. The non relevant atomistic interactions with higher energy are practically unimportant for the dynamics.