Microscopic Theory of Spin Wave Dynamics in Ferromagnetic Films PDF Download

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

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Author: João Milton Pereira
Publisher:
ISBN:
Category : Antiferromagnetism
Languages : en
Pages : 332

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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: 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: Anjan Barman
Publisher: Springer
ISBN: 3319662961
Category : Technology & Engineering
Languages : en
Pages : 166

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This book provides a comprehensive overview of the latest developments in the field of spin dynamics and magnetic damping. It discusses the various ways to tune damping, specifically, dynamic and static control in a ferromagnetic layer/heavy metal layer. In addition, it addresses all optical detection techniques for the investigation of modulation of damping, for example, the time-resolved magneto-optical Kerr effect technique.

Author: João Milton Pereira
Publisher:
ISBN:
Category : Antiferromagnetism
Languages : en
Pages : 0

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

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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: Chunhui Du
Publisher:
ISBN:
Category :
Languages : en
Pages : 137

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Generation and manipulation of spin is of central importance in modern physics. This intense interest is driven in part by exciting new phenomena in spintronics such as spin Hall effects and spin transfer torque as well as by the growth in new tools enabling microscopic studies. Ferromagnetic resonance (FMR) is a powerful technique to study macro-scale spin ensembles, and an effective method to generate pure spin currents. Combined with scanning capability, it can be used as a spin sensitive microscopy with nano-scale spatial resolution to bring fresh insights in spintronics and achieve local excitation, manipulation, and detection of spin. In the first part of this thesis, I will briefly introduce the field of spintronics. In the second chapter, I demonstrate the use of FMR spectroscopy to study the static and dynamics properties of novel materials. In the third chapter, I present the FMR spin pumping technique in ferromagnetic material/normal metal bilayer to characterize the spin Hall angles for a series of 3d, 4d, and 5d transition metals with widely varying spin-orbit coupling strengths and demonstrate that both atomic number, Z, and d electron count play important roles in spin Hall physics. Those work studies the spin dynamics and transport across the interface defined by material discontinuity in macro-scale sample. To study nano-scale structures, in the forth and fifth chapters, I describe probing and imaging spin dynamics using spin wave modes confined into microscopic volumes in a ferromagnetic film by the spatially inhomogeneous magnetic field of a scanned micromagnetic tip of a ferromagnetic resonance force microscope (FMRFM). It shows the characteristics of the localized mode can be broadly tuned by appropriate selection of the orientation of the tip moment relative to the applied uniform field. Micromagnetic simulations accurately reproduce our experimental results and allow quantitative understanding of the ferromagnetic resonance force microscopy spectra. These results provide a universal method of generating and understanding the tightly confined localized modes in various measurement geometries and material systems with increased freedom in the choice of tip and material, and paves the way to improved spatial resolution for imaging using localized spin wave modes. At last, I demonstrate a design of room temperature FMR force microscope with both imaging and transport capability to study and image spin dynamics and transport across the interface defined by the magnetic textures with nano-scale resolution. The sixth chapter is a conclusion of the entire dissertation.

Author: Paula R. L. Heron
Publisher:
ISBN:
Category : Ferromagnetic materials
Languages : en
Pages : 438

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Author: Gianluca Gubbiotti
Publisher: CRC Press
ISBN: 1000024547
Category : Science
Languages : en
Pages : 264

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Magnonics, a research field that uses spin waves, collective excitations of ordered magnetic materials, or magnons (their quanta) as a tool for signal processing, communication, and computation, has rapidly grown during the past decade because of the low-energy consumption and potential compatibility with next-generation circuits beyond CMOS electronics. The interest in 3D magnonic nanostructures follows the latest trend in conventional electronics based on expansion from 2D planar to 3D vertically integrated structures. To remain on the same technological level, a similar expansion should be realized in magnonics. Following this trend, this book provides an overview of recent developments in the exploitation of the third dimension in magnonics, with special focus on the propagation of spin waves in layered magnonic crystals, spin textures, curved surfaces, 3D nano-objects, and cavity magnonics.