Download or read book Magnetic Thin Films For Spintronic Memory written by Parnika Agrawal and published by . This book was released on 2018 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: Domain walls are regions of spatially non-uniform magnetizations in magnetic materials. They form the boundaries between two or more uniformly magnetized regions called domains. Skyrmions are circular magnetic domains with chiral domain walls that are interesting due to their stability and potential for fast motion. These spin structures can be used to encode Os and Is in spintronic memory. Chiral domain walls and skyrmions have been seen in magnetic thin films sandwiched between non-identical non-magnetic materials which have high spin-orbit coupling and Dzyaloshinskii-Moriya interaction. An optimization of the different physical interactions involved in magnetic thin films can result in stripe and labyrinth domain patterns which can then be transformed into skyrmion lattices. In this thesis, we present a detailed understanding of single- and multi-layer magnetic thin films along with all the relevant physical interactions. We show that inplane magnetic fields stabilize domain walls in thin films with Dzyaloshinskii-Moriya interaction. The application of in-plane magnetic fields is shown to create multi-domain patterns in films where the ground state is uniform magnetization. Next, we study the formation of stripe and labyrinth domain patterns in magnetic films. The domain widths obtained are compared with the predictions of several theoretical models developed over the last 50 years. The appropriate model that works for thin films with strong Dzyaloshinskii-Moriya interaction is identified with the help of micromagnetic simulations. The appropriate model includes effects of finite domain wall width and volume charges inside Neel domain walls. This model is then used to measure the Dzyaloshinskii-Moriya interaction in experimentally grown magnetic thin films. Thereafter, we highlight the role of other design variables such as the thickness of magnetic and non-magnetic layers, the choice of materials, and the role of geometrical confinement in controlling the length scale of the domain patterns. This work generates the necessary knowledge and develops techniques to engineer chiral spin textures in single- and multi-layer magnetic thin films.

Download or read book Development of Novel Electronic and Magnetic Thin Films for Next Generation Spintronics Applications written by Yub Raj Sapkota and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spintronic-based magnetic random-access memory (MRAM) implementing the tunnel magnetoresistance (TMR) effect has various advantages over conventional semiconductor base memory devices, such as non-volatility and potentially high density and scalability. Traditional MRAM design implemented in-plane magnetic switching for the read/write operation which is now recognized to suffer from poor scalability below 60 nm. With the discovery of the spin-transfer torque (STT) effect, where the spin-polarized current is used to switch the ferromagnet, the MRAM design simplified considerably as it eliminated one of the two current-carrying wires that are used to generate the magnetic field required for switching. The thermal stability is further enhanced by using magnetic materials with perpendicular magnetic anisotropy (PMA). In current devices, perpendicular anisotropy is developed at the free magnetic layer (CoFeB) interface with the tunnel barrier (MgO). It is called interfacial-perpendicular anisotropy. However, it has been shown that this design has scaling issues below 20 nm. Materials with volume (bulk) perpendicular magnetic anisotropy should show better scaling without compromising on thermal stability. This dissertation work is focused on growth and physical property investigations of thin films of novel magnetic and electronic materials which are promising for MRAM devices. Leveraging on prior identified materials (both theory and bulk materials experiment) with tetragonal and hexagonal symmetry that support PMA, we have successfully implemented several manganese-based hexagonal Heusler-like Mn3-xFexSn (X=0,1,2) alloys predicted to be high PMA materials. While Mn3Sn thin films are reported in the literature, we are not aware of any thin film reports elsewhere on Fe2MnSn and Mn2FeSn thin films discussed here. All these materials are stabilized in the hexagonal structure which inherently supports perpendicular anisotropy. Specifically, we found that Mn3Sn has low saturation magnetization and high Tc but low magnetic anisotropy. Mn2FeSn has a moderate magnetic moment but low Tc (272 K). Fe2MnSn is the most favorable material among our investigations, with high magnetic anisotropy and high Curie temperature of 548 K, but with a higher than desired magnetization value. The magnetic anisotropy value of Fe2MnSn is estimated to be 0.56 MJ/m3. Such value is in the desirable range for MRAM devices. Our thermal stability calculations indicate that STT-MRAM with Fe2MnSn free layer can scale below 20 nm lateral size for 3nm free layer thickness. While the scaling behavior remains to be investigated experimentally, my work has demonstrated that research into new materials is always an exciting prospect particularly if combined with a theory-driven design approach.

Download or read book Magnetic Memory Technology written by Denny D. Tang and published by John Wiley & Sons. This book was released on 2021-01-07 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: STAY UP TO DATE ON THE STATE OF MRAM TECHNOLOGY AND ITS APPLICATIONS WITH THIS COMPREHENSIVE RESOURCE Magnetic Memory Technology: Spin-Transfer-Torque MRAM and Beyond delivers a combination of foundational and advanced treatments of the subjects necessary for students and professionals to fully understand MRAM and other non-volatile memories, like PCM, and ReRAM. The authors offer readers a thorough introduction to the fundamentals of magnetism and electron spin, as well as a comprehensive analysis of the physics of magnetic tunnel junction (MTJ) devices as it relates to memory applications. This book explores MRAM's unique ability to provide memory without requiring the atoms inside the device to move when switching states. The resulting power savings and reliability are what give MRAM its extraordinary potential. The authors describe the current state of academic research in MRAM technology, which focuses on the reduction of the amount of energy needed to reorient magnetization. Among other topics, readers will benefit from the book's discussions of: An introduction to basic electromagnetism, including the fundamentals of magnetic force and other concepts An thorough description of magnetism and magnetic materials, including the classification and properties of magnetic thin film properties and their material preparation and characterization A comprehensive description of Giant magnetoresistance (GMR) and tunneling magnetoresistance (TMR) devices and their equivalent electrical model Spin current and spin dynamics, including the properties of spin current, the Ordinary Hall Effect, the Anomalous Hall Effect, and the spin Hall effect Different categories of magnetic random-access memory, including field-write mode MRAM, Spin-Torque-Transfer (STT) MRAM, Spin-Orbit Torque (SOT) MRAM, and others Perfect for senior undergraduate and graduate students studying electrical engineering, similar programs, or courses on topics like spintronics, Magnetic Memory Technology: Spin-Transfer-Torque MRAM and Beyond also belongs on the bookshelves of engineers and other professionals involved in the design, development, and manufacture of MRAM technologies.

Download or read book Ultrathin Magnetic Structures IV written by Bretislav Heinrich and published by Springer Science & Business Media. This book was released on 2004-12-13 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ability to understand and control the unique properties of interfaces has created an entirely new field of magnetism which already has a profound impact in technology and is providing the basis for a revolution in electronics. The last decade has seen dramatic progress in the development of magnetic devices for information technology but also in the basic understanding of the physics of magnetic nanostructures. Volume III describes thin film magnetic properties and methods for characterising thin film structure topics that underpin the present 'spintronics' revolution in which devices are based on combined magnetic materials and semiconductors. The present volume (IV) deals with the fundamentals of spintronics: magnetoelectronic materials, spin injection and detection, micromagnetics and the development of magnetic random access memory based on GMR and tunnel junction devices. Together these books provide readers with a comprehensive account of an exciting and rapidly developing field. The treatment is designed to be accessible both to newcomers and to experts already working in this field who would like to get a better understanding of this very diversified area of research.

Download or read book Ultrathin Magnetic Structures III written by J.A.C. Bland and published by Springer Science & Business Media. This book was released on 2005-12-06 with total page 329 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ability to understand and control the unique properties of interfaces has created an entirely new field of magnetism which already has a profound impact in technology and is providing the basis for a revolution in electronics. The last decade has seen dramatic progress in the development of magnetic devices for information technology but also in the basic understanding of the physics of magnetic nanostructures. This volume describes thin film magnetic properties and methods for characterising thin film structure topics that underpin the present 'spintronics' revolution in which devices are based on combined magnetic materials and semiconductors. Volume IV deals with the fundamentals of spintronics: magnetoelectronic materials, spin injection and detection, micromagnetics and the development of magnetic random access memory based on GMR and tunnel junction devices. Together these books provide readers with a comprehensive account of an exciting and rapidly developing field. The treatment is designed to be accessible both to newcomers and to experts already working in this field who would like to get a better understanding of this very diversified area of research.

Download or read book Spin Dynamics in Magnetic Thin Films and Spintronics Devices written by Yunpeng Chen and published by . This book was released on 2016 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic materials are the essential parts of advanced magnetic recording and microwave devices. All the applications require the control of the magnetization orientation that is studied as magnetic dynamics. In a magnetic recording device, such as hard disk drive (HDD), the digital information is stored as the magnetization direction of magnetic domains. To rewrite the information, one needs to reverse the magnetization. With the increase of areal density, the magnetic anisotropy is enhanced to overcome the thermal fluctuations. Consequently, the magnetic switching becomes more difficult. Microwave assisted magnetization reversal (MAMR) is developed to lower the switching field by exciting large angle precession of magnetization. Damping constant, as a parameter describing the dissipation of magnetic materials, plays a critical role in MAMR. In this thesis, I theoretically and experimentally study the damping dependence of MAMR in micro-size magnetic dots. Based on the study, MAMR is more efficient when the damping of the magnetic dot is small. Magnetic random access memory (MRAM) based on magnetic tunnel junctions (MTJs) is a novel magnetic recording device that has the potential to replace HDD due to its fast read/write rate. Moreover, to keep increasing the recording density, the magnetic media with perpendicular magnetic anisotropy (PMA) replaced the in-plane magnetic recording media. In this work, the magnetic thin films such as Co/Pd multilayers and Ta/CoFeB/MgO were fabricated to be with PMA. Based on the PMA thin films, the MTJs were developed with optimized deposition conditions and post-annealing. We observed above 60% TMR in Ta/CoFeB/MgO/CoFeB based perpendicular junctions. The voltage controlled magnetic anisotropy (VCMA) was demonstrated in those MTJs, which is an efficient technique to control the magnetization via an electric field. The spin transfer torques were also characterized in Ta/CoFeB/MgO structures with PMA. The microwave response is another useful property of magnetic materials. The ferromagnetic resonance (FMR) of typical ferromagnetic materials like Fe, Co, Ni and their alloys are in the gigahertz range. Therefore, the magnetic thin films have been widely utilized in microwave devices such as bandpass filters, insulators, and oscillators. Conventionally, electromagnets generate a magnetic field to control the resonance frequency, which is bulky, noisy, slow and energy consuming. By realizing the huge effective field due to exchange interaction, a novel scheme was demonstrated to shift the resonance frequency of the optical mode in magnetic bilayers with interlayer exchange interaction. A maximum 20 GHz tunable range was achieved in a spin-valve base spintronics microwave device in the experiment. A dynamic tuning of the resonance frequency as high as 9 GHz was demonstrated via temperature controlled exchange interaction.

Download or read book Ultrathin Magnetic Structures IV written by Bretislav Heinrich and published by Springer. This book was released on 2004-12-13 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ability to understand and control the unique properties of interfaces has created an entirely new field of magnetism which already has a profound impact in technology and is providing the basis for a revolution in electronics. The last decade has seen dramatic progress in the development of magnetic devices for information technology but also in the basic understanding of the physics of magnetic nanostructures. Volume III describes thin film magnetic properties and methods for characterising thin film structure topics that underpin the present 'spintronics' revolution in which devices are based on combined magnetic materials and semiconductors. The present volume (IV) deals with the fundamentals of spintronics: magnetoelectronic materials, spin injection and detection, micromagnetics and the development of magnetic random access memory based on GMR and tunnel junction devices. Together these books provide readers with a comprehensive account of an exciting and rapidly developing field. The treatment is designed to be accessible both to newcomers and to experts already working in this field who would like to get a better understanding of this very diversified area of research.

Download or read book Ultrathin Magnetic Structures III written by J.A.C. Bland and published by Springer. This book was released on 2004-12-13 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ability to understand and control the unique properties of interfaces has created an entirely new field of magnetism which already has a profound impact in technology and is providing the basis for a revolution in electronics. The last decade has seen dramatic progress in the development of magnetic devices for information technology but also in the basic understanding of the physics of magnetic nanostructures. This volume describes thin film magnetic properties and methods for characterising thin film structure topics that underpin the present 'spintronics' revolution in which devices are based on combined magnetic materials and semiconductors. Volume IV deals with the fundamentals of spintronics: magnetoelectronic materials, spin injection and detection, micromagnetics and the development of magnetic random access memory based on GMR and tunnel junction devices. Together these books provide readers with a comprehensive account of an exciting and rapidly developing field. The treatment is designed to be accessible both to newcomers and to experts already working in this field who would like to get a better understanding of this very diversified area of research.

Download or read book Interplay of Magnetic Anisotropy and Magnetization Reversal in Ferromagnetic Thin Films for Spintronics Applications written by Soumalya Paul and published by . This book was released on 2016 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: High spin-polarization in a magnetic material is essential for excellent performance of future spintronic devices and in that regard, half-metallic materials are promising candidates when incorporated into magnetoresistive devices such as magnetic tunnel junctions (MTJs) for spin transfer torque magnetic random access memory (STT-MRAM). As there is an increasing thrust toward device miniaturization and achieving faster switching times, it is likely that magnetic recording materials will be operating at higher frequencies and hence understanding the interplay between the magnetic anisotropy and the magnetization reversal process is of crucial importance both from technological and fundamental perspectives. Broadband ferromagnetic resonance (FMR) spectroscopy is an excellent tool to probe the dynamic magnetic properties of these half-metallic materials. Our investigation suggests that these low damping materials exhibit 'anisotropic magnetization relaxation' due to misfit dislocation (in case of Heusler CoxFe3-xSi thin films) as well as the presence of 'magnetostatic spin waves' due to the long-range dipolar interaction (in case of rutile CrO2 thin films). Furthermore, vector magneto-optic Kerr effect (MOKE) magnetometry reveals that single crystal CrO2 thin films are magneto-optically anisotropic with two different refractive indices. The structural anisotropy of the tetragonal CrO2 induces the magneto-optical anisotropy. On the other hand, changing the stoichiometry in epitaxial CoxFe3-xSi thin films results in the co-existence of the uniaxial magnetic anisotropy and the cubic magnetic anisotropy. The magnetization reversal processes are associated with the one-jump and two-jump reversal steps that depend critically on the competition between the uniaxial and cubic anisotropies present in these samples.

Download or read book Optoelectronics and Spintronics in Smart Thin Films written by James Ayodele Oke and published by CRC Press. This book was released on 2023-12-06 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: Smart thin films, composed of functional materials deposited in thin layers, have opened new avenues for the development of flexible, lightweight, and high-performance devices. Optoelectronics and Spintronics in Smart Thin Films presents a comprehensive overview of this emerging area and details the current and near future integration of smart thin films in solar cells, and memory storage. Offers an overview of optoelectronics and spintronics Discusses synthesis of smart nanomaterials Describes deposition techniques and characterization of thin films Considers the integration and application of opto-spintronics for technological advancement of solar cells and memory storage devices Focused on advancing research on this evolving subject, this book is aimed at advanced students, researchers, and engineers in materials, chemical, mechanical, and electrical engineering, as well as applied physics.

Download or read book Hung pi y an written by and published by . This book was released on 1935 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ultrathin Magnetic Structures IV written by Bretislav Heinrich and published by Springer Science & Business Media. This book was released on 2005-12-07 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ability to understand and control the unique properties of interfaces has created an entirely new field of magnetism which already has a profound impact in technology and is providing the basis for a revolution in electronics. The last decade has seen dramatic progress in the development of magnetic devices for information technology but also in the basic understanding of the physics of magnetic nanostructures. Volume III describes thin film magnetic properties and methods for characterising thin film structure topics that underpin the present 'spintronics' revolution in which devices are based on combined magnetic materials and semiconductors. The present volume (IV) deals with the fundamentals of spintronics: magnetoelectronic materials, spin injection and detection, micromagnetics and the development of magnetic random access memory based on GMR and tunnel junction devices. Together these books provide readers with a comprehensive account of an exciting and rapidly developing field. The treatment is designed to be accessible both to newcomers and to experts already working in this field who would like to get a better understanding of this very diversified area of research.

Download or read book Spintronics written by Tomasz Blachowicz and published by Walter de Gruyter GmbH & Co KG. This book was released on 2019-05-06 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: Starting from quantum mechanical and condensed matter foundations, this book introduces into the necessary theory behind spin electronics (Spintronics). Equations of spin diffusion, -evolution and -tunelling are provided before an overview is given of simulation of spin transport at the atomic scale. Furthermore, applications are discussed with a focus on elementary spintronics devices such as spin valves, memory cells and hard disk heads.

Download or read book Novel Spin Hall Effect Materials and Artificially Engineered Magnetic Thin Film Heterostructures for Energy efficient Spintronic Memories written by Peng Wang and published by . This book was released on 2022* with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spintronic memories; spin Hall effect; synthetic antiferromagents; skyrmions.

Download or read book Handbook of Nanomagnetism written by Rosa A. Lukaszew and published by CRC Press. This book was released on 2015-10-06 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: This unique handbook compiles and details cutting-edge research in nanomagnetism and its applications in spintronics, magnetoplasmonics, and nonlinear magneto-optics. Fundamental aspects of magnetism relevant to nanodevices and new spin-transfer torque random-access memory (STT-RAM), current-induced domain wall motion memory, and spin torque oscill

Download or read book Metallic Spintronic Devices written by Xiaobin Wang and published by CRC Press. This book was released on 2017-12-19 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metallic Spintronic Devices provides a balanced view of the present state of the art of metallic spintronic devices, addressing both mainstream and emerging applications from magnetic tunneling junction sensors and spin torque oscillators to spin torque memory and logic. Featuring contributions from well-known and respected industrial and academic experts, this cutting-edge work not only presents the latest research and developments but also: Describes spintronic applications in current and future magnetic recording devices Discusses spin-transfer torque magnetoresistive random-access memory (STT-MRAM) device architectures and modeling Explores prospects of STT-MRAM scaling, such as detailed multilevel cell structure analysis Investigates spintronic device write and read optimization in light of spintronic memristive effects Considers spintronic research directions based on yttrium iron garnet thin films, including spin pumping, magnetic proximity, spin hall, and spin Seebeck effects Proposes unique solutions for low-power spintronic device applications where memory is closely integrated with logic Metallic Spintronic Devices aims to equip anyone who is serious about metallic spintronic devices with up-to-date design, modeling, and processing knowledge. It can be used either by an expert in the field or a graduate student in course curriculum.

Download or read book Modeling Fabrication and Characterization of Magnetic Thin Films for Integrated Inductor and MRAM Applications written by Benjamin Buford and published by . This book was released on 2016 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic thin films have potential to improve devices such as on-chip inductors, and enable new technologies such as magnetic random access memory (MRAM). The use of magnetic cores in on-chip inductors is typically limited to applications well under 1 GHz. At higher frequencies, the performance of the magnetic core is severely limited by eddy current losses and ferromagnetic resonance. This work investigates the feasibility of using shape anisotropy to increase the ferromagnetic resonance frequency and thus allow the use of thin-film magnetic cores at frequencies up to 3 GHz. Magnetic cores are fabricated on top of existing chip- scale inductors. The effect of core shape and oxide layers, which are added to reduce eddy currents, on the magnetic properties of the film are investigated. Magnetic tunnel junctions (MTJs) are of interest in MRAM and spintronic logic circuit ap- plications due to their non-volatility, low-power operation, and size scalability. One limitation to the creation of scalable magnetic random access memory is thermal stability. For large devices, this energy barrier is proportional to the exchange stiffness of a material. Typically the thermal stability is measured in fabricated MRAM devices, and is used to back-calculate the exchange stiff- ness. This work presents a novel approach which uses images of magnetic domains, in conjunction with vibrating sample magnetometer and ferromagnetic resonance measurements, to measure the exchange stiffness in unpatterned films. This allows for estimation of the thermal stability that can be obtained by a given magnetic free layer without need to fabricate and measure completed de- vices. Using this approach, the exchange stiffness and expected thermal stability in MgO / CoFeB / spacer / CoFeB / MgO free layer structures with various spacer layer materials and thicknesses are compared.