Download or read book Magnetization Dynamics in Coupled Magnetic Systems written by Stefan Horst Klingler and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Magnetization Dynamics in Magnetically Coupled Heterostructures written by Alexander Kaiser and published by Forschungszentrum Jülich. This book was released on 2009 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nonlinear and Chaotic Magnetization Dynamics in Single domain Nanoparticles and Exchange coupled Thin films written by Aaron Michael Ferona and published by . This book was released on 2018 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation, we study two fundamental issues in nonlinear magnetism: the nonlinear dynamics of nanoparticles and the nonlinear dynamics of exchange-coupled thin-films. The behavior of a uniformly magnetized domain of ellipsoidal shape subject to a static external field and oscillatory external driving field is analyzed near bifurcation events. The analysis includes the effects of both linear and circularly polarized driving fields and is performed using numerical simulations of the Landau-Lifshitz-Gilbert (LLG) equation. Under a linearly polarized driving field, the LLG equation is a nonautonomous differential equation which can lead to complex magnetization motions, such as bistability, multi-periodic orbits, quasiperiodicity and chaos. Under a circular polarized driving field, the LLG equation can be written in autonomous form by transforming to the frame rotating with the driving field. The autonomous nature allows one to perform a fixed point analysis of the system for select demagnetization factors. Similarities and differences between the driven systems are highlighted through, bifurcation diagrams, phase portraits, basins of attraction and Lyapunov exponents. Magnetization switching, prolonged transients, quasiperiodicity, and chaos are observed with both linear and circularly polarized driving fields in the magnetic systems investigated. We also investigate the dynamics of exchange-coupled ferromagnetic films in the nonlinear limit and find a number of interesting features. These include the following: 1) A power-dependent localization of the magnetization oscillations; 2) A nonlinear mixing of the acoustic and optic modes in the antiferromagnetically coupled system leads to quasiperiodic and multi-periodic composite modes; 3) Ferromagnetic resonance experiments will show new absorption peaks (in the 20-50 GHz range) which have a rapid increase in strength with input power. As with the case of the uniformly magnetized domain, the results are calculated through linearization techniques and numerical solutions of the LLG equation. The nonlinear (and linear) behavior is illustrated through Poincare section bifurcation diagrams and power absorption curves.
Download or read book Magnetization Oscillations and Waves written by A.G. Gurevich and published by CRC Press. This book was released on 2020-12-17 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by two well-known researchers in the field, this useful reference takes an applied approach to high frequency processes including oscillations and waves in ferromagnets, antiferromagnets, and ferrimagnets. Problems evaluated include ferromagnetic and antiferromagnetic resonances, spin waves, nonlinear processes, and high frequency manifestations of interactions between the magnetic system and other systems of magnetically ordered substances as elastic waves and charge carriers. Unlike previous monographs on this subject, which are highly theoretical and written for very advanced readers, this book requires only an average college background in mathematics and experimental physics. It will be a valuable addition to the library of engineers and scientists in research and development for communications applications, and scientists interested in nonlinear magnetic phenomena. It also serves as an excellent introduction to the topic for newcomers in the field. Magnetization Oscillations and Waves not only presents results but also shows readers how to obtain them; most formulas are derived with so many details that readers can reproduce them. The book includes many summaries and tables and detailed references to significant work in the area by European researchers.
Download or read book Magnetization Dynamics in Exchange Coupled Multilayers written by David George Newman and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Magnetism of Surfaces Interfaces and Nanoscale Materials written by Robert E. Camley and published by Elsevier. This book was released on 2015-10-27 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the past 30 years, magnetic research has been dominated by the question of how surfaces and interfaces influence the magnetic and transport properties of nanostructures, thin films and multilayers. The research has been particularly important in the magnetic recording industry where the giant magnetoresistance effect led to a new generation of storage devices including hand-held memories such as those found in the ipod. More recently, transfer of spin angular momentum across interfaces has opened a new field for high frequency applications.This book gives a comprehensive view of research at the forefront of these fields. The frontier is expanding through dynamic exchange between theory and experiment. Contributions have been chosen to reflect this, giving the reader a unified overview of the topic. Addresses both theory and experiment that are vital for gaining an essential understanding of topics at the interface between magnetism and materials science Chapters written by experts provide great insights into complex material Discusses fundamental background material and state-of-the-art applications, serving as an indispensable guide for students and professionals at all levels of expertise Stresses interdisciplinary aspects of the field, including physics, chemistry, nanocharacterization, and materials science Combines basic materials with applications, thus widening the scope of the book and its readership
Download or read book Nonlinear Magnetization Dynamics in Nanosystems written by Isaak D. Mayergoyz and published by Elsevier. This book was released on 2009-04-20 with total page 479 pages. Available in PDF, EPUB and Kindle. Book excerpt: As data transfer rates increase within the magnetic recording industry, improvements in device performance and reliability crucially depend on the thorough understanding of nonlinear magnetization dynamics at a sub-nanoscale level. This book offers a modern, stimulating approach to the subject of nonlinear magnetization dynamics by discussing important aspects such as the Landau-Lifshitz-Gilbert (LLG) equation, analytical solutions, and the connection between the general topological and structural aspects of dynamics. An advanced reference for the study and understanding of nonlinear magnetization dynamics, it addresses situations such as the understanding of spin dynamics in short time scales and device performance and reliability in magnetic recording. Topics covered include nonlinear magnetization dynamics and the Landau-Lifshitz-Gilbert equation, nonlinear dynamical systems, spin waves, ferromagnetic resonance and pulsed magnetization switching. The book explains how to derive exact analytical solutions for the complete nonlinear problem and emphasises the connection between the general topological and structural aspects of nonlinear magnetization dynamics and the discretization schemes better suited to its numerical study. It is an exceptional research tool providing an advanced understanding of the study of magnetization dynamics in situations of fundamental and technological interest.
Download or read book Spin Transport and Magnetization Dynamics in Various Magnetic Systems written by Shulei Zhang and published by . This book was released on 2014 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: The general theme of the thesis is the interplay between magnetization dynamics and spin transport. The main presentation is divided into three parts. The first part is devoted to deepening our understanding on magnetic damping of ferromagnetic metals, which is one of the long-standing issues in conventional spintronics that has not been completely understood. For a nonuniformly-magnetized ferromagnetic metal, we find that the damping is nonlocal and is enhanced as compared to that in the uniform case. It is therefore necessary to generalize the conventional Landau-Lifshitz-Gilbert equation to include the additional damping. In a different vein, the decay mechanism of the uniform precession mode has been investigated. We point out the important role of spin-conserving electron-magnon interaction in the relaxation process by quantitatively examining its contribution to the ferromagnetic resonance linewidth. In the second part, a transport theory is developed for magnons which, in addition to conduction electrons, can also carry and propagate spin angular momentum via the magnon current. We demonstrate that the mutual conversion of magnon current and spin current may take place at magnetic interfaces. We also predict a novel magnon-mediated electric drag effect in a metal/magnetic-insulator/metal trilayer structure. This study may pave the way to the new area of insulator-based spintronics. In the third part of thesis, particular attention is paid to the influence the spin orbit coupling on both charge and spin transport. We theoretically investigate magnetotransport anisotropy and the conversion relations of spin and charge currents in various magnetic systems, and apply our results to interpret recent experiments.
Download or read book INVESTIGATION OF MAGNETIZATION written by Jian Chen and published by Open Dissertation Press. This book was released on 2017-01-26 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Investigation of Magnetization Dynamics in Nanostructures" by Jian, Chen, 陳健, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: This thesis investigated magnetization dynamics in nanostructures. Magnetization can be considered as an ensemble of large number of spins. In a macrospin model, magnetization is assumed to be spatially uniform so that it can be treated as a classical vector. Typically a Landau-Lifshitz-Gilbert (LLG) equation is used to described the dynamics of magnetization. The LLG equation is usually derived phenomenologically and the parameters of the equation needs to be tuned in order to comply with the experiments. Study of the magnetization dynamics from first principles is still insufficient. In this thesis, by using the time dependent Green's function theory, magnetization dynamics is studied in two systems: quantum dot with normal leads, and quantum dot with ferromagnetic leads. Expressions of intrinsic Gilbert damping tensor as well as fluctuating torque are derived in terms of Green's function. Our expression of Gilbert damping tensor resembles the one derived from scattering matrix theory in the limit of low temperatures and wide band approximation, but is suitable for general case. Spin continuity equation of the system is also discussed, which shows how spin current is included in the equation of magnetization dynamics. Recently spin torque effect due to the presence of Rashba spin-orbit coupling (RSOC) opens the possibility of a new mechanism to manipulate magnetization. Currently most of the studies focused on infinite two dimensional electron gas (2DEG) system where current is driven by an external electric field. A semiclassical Boltzmann (SCB) transport equation was used and the nonequilibrium spin density was found to be linearly proportional to the charge current density. However, systematic investigation of such effect in a mesoscopic system beyond the semiclassical Boltzmann description has not been reported. It is purpose of this thesis to fill this gap. In this thesis, magnetization dynamics is investigated in a finite 2DEG system where current is driven by bias instead of electric field. Rashba spin orbit coupling (RSOC) in 2D ferromagnetic materials generates spin polarization in 2DEG, thus a spin torque is induced. Magnetization dynamics of the ferromagnetic 2DEG is investigated in a tight binding model, which shows similar magnetic field assist switching effect as in the experiment. Our formalism is feasible for the first principle calculation of magnetization dynamics. Subjects: Nanostructures Electromagnetism
Download or read book Atomistic Spin Dynamics written by Olle Eriksson and published by Oxford University Press. This book was released on 2017 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several large experimental facilities that focus on detection and probing magnetization dynamics have been realized in Europe, USA and Japan. This book covers theoretical and practical aspects of the vibrant and emerging research field of magnetization dynamics.
Download or read book Magnetization Dynamics of Nanostructured Ferromagnetic Rings and Rectangular Elements written by Fabian Giesen and published by Cuvillier Verlag. This book was released on 2005 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spin Dynamics and Damping in Ferromagnetic Thin Films and Nanostructures written by Anjan Barman and published by Springer. This book was released on 2017-12-27 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Handbook of Spintronics written by Yongbing Xu and published by Springer. This book was released on 2015-10-14 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over two volumes and 1500 pages, the Handbook of Spintronics will cover all aspects of spintronics science and technology, including fundamental physics, materials properties and processing, established and emerging device technology and applications. Comprising 60 chapters from a large international team of leading researchers across academia and industry, the Handbook provides readers with an up-to-date and comprehensive review of this dynamic field of research. The opening chapters focus on the fundamental physical principles of spintronics in metals and semiconductors, including an introduction to spin quantum computing. Materials systems are then considered, with sections on metallic thin films and multilayers, magnetic tunnelling structures, hybrids, magnetic semiconductors and molecular spintronic materials. A separate section reviews the various characterisation methods appropriate to spintronics materials, including STM, spin-polarised photoemission, x-ray diffraction techniques and spin-polarised SEM. The third part of the Handbook contains chapters on the state of the art in device technology and applications, including spin valves, GMR and MTJ devices, MRAM technology, spin transistors and spin logic devices, spin torque devices, spin pumping and spin dynamics and other topics such as spin caloritronics. Each chapter considers the challenges faced by researchers in that area and contains some indications of the direction that future work in the field is likely to take. This reference work will be an essential and long-standing resource for the spintronics community.
Download or read book Magnetic Order and Coupling Phenomena written by Christian Schubert and published by Springer. This book was released on 2014-06-03 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Magnetization Dynamics Using Ultrashort Magnetic Field Pulses written by Ioan Tudosa and published by . This book was released on 2005 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ultrafast Magnetization Dynamics written by Simon Woodford and published by Forschungszentrum Jülich. This book was released on 2008 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dynamical Properties of Unconventional Magnetic Systems written by A.T. Skjeltorp and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetism encompasses a wide range of systems and physical phenomena, and its study has posed and exposed both important fundamental problems and many practical applications. Recently, several entirely new phenomena have thus been discovered, generated through cooperative behaviour which could not have been predicted from a knowledge of `one-spin' states. At the same time, advances in sample preparation, experimental technique, apparatus and radiation sources, have led to increasing precision in the investigation and exposure of greater subtleties in magnetic thin films, multilayers and other systems. Examples of unexpected and conceptually new phenomena occur in strongly correlated and fluctuating quantum systems, producing effects such as Haldane and spin-Peierls gaps, solitons, quantum spin glasses and spin liquids. The discovery and elucidation of these `emerging properties' is a central theme in modern condensed matter physics. The present book comprises a series of chapters by world experts, covering both theoretical and experimental aspects. The approach is pedagogical and tutorial, but fully up to date, covering the latest research. The level is appropriate to graduate researchers who may either be just moving into the field or who are already active in condensed matter physics.
