Spin Torque Effects In Mgo Based Magnetic Tunnel Junctions
DOWNLOAD
Download Spin Torque Effects In Mgo Based Magnetic Tunnel Junctions PDF/ePub or read online books in Mobi eBooks. Click Download or Read Online button to get Spin Torque Effects In Mgo Based Magnetic Tunnel Junctions book now. This website allows unlimited access to, at the time of writing, more than 1.5 million titles, including hundreds of thousands of titles in various foreign languages. If the content not found or just blank you must refresh this page
Spin Torque Effects In Mgo Based Magnetic Tunnel Junctions
DOWNLOAD
Author : Hsin-wei Tseng
language : en
Publisher:
Release Date : 2013
Spin Torque Effects In Mgo Based Magnetic Tunnel Junctions written by Hsin-wei Tseng and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2013 with categories.
This thesis work focuses on understanding the fundamentals of the spintorque effect in MgO-based high tunneling magnetoresistance (TMR) magnetic tunnel junction (MTJ) nanopillar geometry devices. In order to achieve this goal, I have successfully established a reliable and repeatable high TMR and low resistance-area (RA) product MgO sputtering process at Cornell. Currently, we are capable of sputtering TMR (>100% with RA
Interfacial Effects In Fecob Based Magnetic Tunnel Junctions And Spin Hall Effect Bi Layer Structures
DOWNLOAD
Author : Yun Li
language : en
Publisher:
Release Date : 2014
Interfacial Effects In Fecob Based Magnetic Tunnel Junctions And Spin Hall Effect Bi Layer Structures written by Yun Li and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2014 with categories.
The transfer of spin angular momentum from a spin-polarized current to a ferromagnet can generate sufficient torque to reorient the magnet's moment, thus this effect has prospective applications in spintronics. In this dissertation, the main theme of my work has been the study of spin-transfer-driven ferromagnetic resonance (STFMR) signals to understand what is the interfacial effects on the spin transfer torque (STT) in magnetic tunnel junction (MTJ) devices with a nanopillar geometry and bilayer spin Hall effect structures. In the first part of my work, I have studied the bias dependence of the spin transfer torques in the as-grown and annealed FeCoB/MgO/FeCoB MTJs by ST-FMR measurement. The motivation of this work was to understand the important mechanisms contributing to the in-plane torque with a view to optimizing the switching current of devices. I have found the annealing reduces the inelastic tunneling component of the junction conductance, and creates or enhances a peak at about 0.15V above the Fermi level in the density of states of the minority band of the electrodes, which may be the reason for the asymmetry of the bias dependence of the in-plane torque. This peak location is essentially the same as the peak of the minority band states that has previously observed on the surface of bcc (100) Fe. The existence of these interfacial states can also explain the asymmetry of the TMR, and the bias dependence of both G AP and GP . As a function of temperature, my experimental STTs can be explained by magnon contributions. My results show that with a relative increase of 50% in tunneling MR, however, both in-plane torque and perpendicular torque have been depressed at low temperature, indicating that magnon assisted tunneling, which results in a spin-flip process for the tunneling electron, has a negative contribution to the spin polarization, but plays a positive role in STT, with the latter consistent with recent theoretical predictions. In the second part of my work, I have studied the spin-torque effects on the FeCoB/W bi-layer structures with different W phases. The motivation of this work was to investigate the spin Hall and spin pumping effects in this system. I have observed a greatly enhanced magnetic damping coefficient for the Fe40Co40B20 layer with [alpha]-W, and I tentatively attribute these results to a significantly enhanced spin pumping effect in [alpha]-W, relative to that in [beta]-W. Magnetization measurements indicate that the two different types of Fe40Co40B20/W bilayers also have substantially different interfacial magnetic anisotropy coefficients.
Spin Transfer Torques In Mgo Based Magnetic Tunnel Junctions
DOWNLOAD
Author : Kerstin Bernert
language : en
Publisher:
Release Date : 2014
Spin Transfer Torques In Mgo Based Magnetic Tunnel Junctions written by Kerstin Bernert and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2014 with categories.
Spin Transfer Torque Magnetisation Switching In Mgo Based Magnetic Tunnel Junctions
DOWNLOAD
Author : Kaan Oguz
language : en
Publisher:
Release Date : 2010
Spin Transfer Torque Magnetisation Switching In Mgo Based Magnetic Tunnel Junctions written by Kaan Oguz and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2010 with categories.
Characterization Of Spin Transfer Torque And Magnetization Manipulation In Magnetic Nanostructures
DOWNLOAD
Author : Chen Wang
language : en
Publisher:
Release Date : 2012
Characterization Of Spin Transfer Torque And Magnetization Manipulation In Magnetic Nanostructures written by Chen Wang and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2012 with categories.
This dissertation describes a number of research projects with the common theme of manipulating the magnetization of a nanoscale magnet through electrical means, and the major part is devoted to exploring the effect of spin angular momentum transfer from a spin-polarized current to a nanomagnet, which we call spin transfer torque. Spin transfer torque is a promising new mechanism to "write" magnetic storage elements in magnetic random access memory (MRAM) devices with magnesium oxide (MgO)-based magnetic tunnel junction (MTJ) architecture. The first part of our work aims at a quantitative measurement of the spin transfer torque exerted on one of the ferromagnetic electrodes in exactly this type of tunneling structures used for MRAM applications. We use a technique called spin-transfer-driven ferromagnetic resonance (ST-FMR), where we apply a microwave-frequency oscillating current to resonantly excite magnetic precession, and we describe two complementary methods to detect this precession. We resolve previous controversies over the bias dependence of spin transfer torque, and present the first quantitative measurement of spin transfer torque in MgO-based MTJs in full bias range. We also analyze and test the potential to use the ST-FMR technique for microwave detection and microwave amplification. In the second part of the our work, we fabricate ferromagnetic nanoparticles made of CoFeB or Co embedded in the MgO tunnel barrier of a typical magnetic tunnel junction device, and study the spin transfer torque exerted on these nanoparticles 2-3 nm in size. We present the first evidence of spin transfer torque in magnetic nanoparticles insulated from electrodes by mapping out the switching phase diagram of a single nanoparticle. We also study ferromagnetic resonance of a small number of nanoparticles induced by spin transfer torque, with the goal of approaching single electron tunneling regime. The last part of our work explores a dramatically different way to manipulate magnetization electrically. We couple a ferromagnet to a multiferroic material, bismuth ferrite (BiFeO3), by exchange bias interaction, and try to manipulate the ferromagnet by ferroelectric switching of the BiFeO3.
Spin Transfer Torque Based Devices Circuits And Memory
DOWNLOAD
Author : Brajesh Kumar Kaushik
language : en
Publisher: Artech House
Release Date : 2016-10-31
Spin Transfer Torque Based Devices Circuits And Memory written by Brajesh Kumar Kaushik and has been published by Artech House this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016-10-31 with Technology & Engineering categories.
This first-of-its-kind resource is completely dedicated to spin transfer torque (STT) based devices, circuits, and memory. A wide range of topics including, STT MRAMs, MTJ based logic circuits, simulation and modeling strategies, fabrication of MTJ CMOS circuits, non-volatile computing with STT MRAMs, all spin logic, and spin information processing are explored. State-of-the-art modeling and simulation strategies of spin transfer torque based devices and circuits in a lucid manner are covered. Professional engineers find practical guidance in the development of micro-magnetic models of spin-torque based devices in object-oriented micro-magnetic framework (OOMMF) and compact modeling of STT based magnetic tunnel junctions in Verilog-A. The performance parameters and design aspects of STT MRAMs and MTJ based hybrid spintronic CMOS circuits are covered and case studies are presented demonstrating STT-MRAM design and simulation with a detailed analysis of results. The fundamental physics of STT based devices are presented with an emphasis on new advancements from recent years. Advanced topics are also explored including, micromagnetic simulations, multi-level STT MRAMs, giant spin Hall Effect (GSHE) based MRAMs, non-volatile computing, all spin logic and all spin information processing.
Engineering Of Metallic Multilayers And Spin Transfer Torque Devices
DOWNLOAD
Author : Jimmy J. Kan
language : en
Publisher:
Release Date : 2014
Engineering Of Metallic Multilayers And Spin Transfer Torque Devices written by Jimmy J. Kan and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2014 with categories.
This dissertation explores in detail the nanofabrication and characterization of ultrathin metallic multilayers designed for the study of several electronic, magnetic, and optical phenomena. Several topics are covered, but the primary focus lies in the investigation and optimization of various sputter deposited thin-film structures with perpendicular magnetic anisotropy (PMA) for their incorporation into MgO-based magnetic tunnel junctions (MTJ). MTJs with these materials systems can then be ultimately applied towards functional spin-transfer-torque magnetoresistive RAM (STT-MRAM) technologies. As multiple topics are to be covered, this dissertation is roughly sub-divided into two parts: (i) full film materials investigation and (ii) device level characterization. (i) Full films materials investigation involved the exploration and optimization of multilayer systems such as Co/Pt, Co/Ni, and Co/Pd as well as crystalline alloys such as CoFeB and CoCrPt. Once identified, these materials were used in the development of perpendicular synthetic antiferromagnet (pSAF) systems. A separate study was performed to evaluate the free layers in pMTJ thin film stacks, focusing on substrate, deposition, and capping effects that contribute to interfacial PMA in MgO/CoFeB-like systems. (ii) A variety of magnetotransport techniques were implemented to study current-induced magnetic reversal of both in-plane and perpendicular MRAM MTJs. The set of magnetotransport tools developed includes both quasi-static field/current methods as well as high-speed transport techniques and have been used to probe key parameters of MRAM cells such as switching voltage, energy barrier, bit-error rates, and spin-torque efficiency. A population of MTJs was studied to analyze the behavior of normal and tail-bit devices. It was discovered through low-temperature magnetotransport measurements that these tail bit MTJs are prone to nucleation of metastable intermediate states and have poor spin-filtering capabilities. Several sizes of perpendicular MTJs were characterized by electrical stress and field sweeping techniques and found to have a variety of defects based on poor MgO/CoFeB interfacial anisotropy. The importance of proper MgO/CoFeB interface engineering is also emphasized in this section as it affects so many of the measurable metrics by which we gauge STT-MRAM as a viable technology.
Handbook Of Spin Transport And Magnetism
DOWNLOAD
Author : Evgeny Y. Tsymbal
language : en
Publisher: CRC Press
Release Date : 2016-04-19
Handbook Of Spin Transport And Magnetism written by Evgeny Y. Tsymbal and has been published by CRC Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016-04-19 with Science categories.
In the past several decades, the research on spin transport and magnetism has led to remarkable scientific and technological breakthroughs, including Albert Fert and Peter Grunberg's Nobel Prize-winning discovery of giant magnetoresistance (GMR) in magnetic metallic multilayers. Handbook of Spin Transport and Magnetism provides a comprehensive, bal
Spin Polarized Current Phenomena In Magnetic Tunnel Junctions
DOWNLOAD
Author : Li Gao
language : en
Publisher:
Release Date : 2009
Spin Polarized Current Phenomena In Magnetic Tunnel Junctions written by Li Gao and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2009 with categories.
Magnetic Memory Technology
DOWNLOAD
Author : Denny D. Tang
language : en
Publisher: John Wiley & Sons
Release Date : 2021-01-07
Magnetic Memory Technology written by Denny D. Tang and has been published by John Wiley & Sons this book supported file pdf, txt, epub, kindle and other format this book has been release on 2021-01-07 with Science categories.
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.