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Full-Text Articles in Physics
Effects Of B And C Doping On Tunneling Magnetoresistance In Cofe/Mgo Magnetic Tunnel Junctions, Andy Paul Chen, John D. Burton, Evgeny Y. Tsymbal, Yuan Ping Feng, Jingsheng Chen
Effects Of B And C Doping On Tunneling Magnetoresistance In Cofe/Mgo Magnetic Tunnel Junctions, Andy Paul Chen, John D. Burton, Evgeny Y. Tsymbal, Yuan Ping Feng, Jingsheng Chen
Evgeny Tsymbal Publications
Using density-functional theory calculations, we investigate the dominant defects formed by boron (B) and carbon (C) impurities in a CoFe/MgO/CoFe magnetic tunnel junction (MTJ) and their influence on conductivity and tunneling magnetoresistance (TMR). We find that, in the O-poor conditions relevant to experiment, B forms the substitutional defect BCo and C forms the interstitial site Ci at the CoFe/MgO interface. The C-doped MTJ is predicted to have a significantly higher TMR than the B-doped MTJ. This is due to interface state densities associated with the majority spin Δ1-symmetry bands being more heavily suppressed by the B …
Tunneling Anisotropic Magnetoresistance In A Magnetic Tunnel Junction With Half-Metallic Electrodes, John D. Burton, Evgeny Y. Tsymbal
Tunneling Anisotropic Magnetoresistance In A Magnetic Tunnel Junction With Half-Metallic Electrodes, John D. Burton, Evgeny Y. Tsymbal
Evgeny Tsymbal Publications
Tunneling anisotropic magnetoresistance (TAMR) is the difference in resistance of a magnetic tunnel junction due to a change in magnetization direction of one or both magnetic electrodes with respect to the flow of current. We present the results of first-principles density functional calculations of the TAMR effect in magnetic tunnel junctions with La0.7Sr0.3MnO3 (LSMO) electrodes and a SrTiO3 (STO) tunneling barrier. We find an ∼500% difference in resistance between magnetization in the plane and out of the plane. This large TAMR effect originates from the half-metallic nature of LSMO: When magnetization is out of …
Electric Control Of Spin Injection Into A Ferroelectric Semiconductor, Xiaohui Liu, John D. Burton, M. Ye. Zhuravlev, Evgeny Y. Tsymbal
Electric Control Of Spin Injection Into A Ferroelectric Semiconductor, Xiaohui Liu, John D. Burton, M. Ye. Zhuravlev, Evgeny Y. Tsymbal
Evgeny Tsymbal Publications
Electric-field control of spin-dependent properties has become one of the most attractive phenomena in modern materials research due to the promise of new device functionalities. One of the paradigms in this approach is to electrically toggle the spin polarization of carriers injected into a semiconductor using ferroelectric polarization as a control parameter. Using first-principles density-functional calculations, we explore the effect of ferroelectric polarization of electron-doped BaTiO3 (n-BaTiO3) on the spin-polarized transmission across the SrRuO3/n-BaTiO3(001) interface. Our study reveals that, in this system, the interface transmission is negatively spin polarized …
Interface Effects In Spin-Dependent Tunneling, Evgeny Y. Tsymbal, Kirill D. Belashchenko, Julian P. Velev, Sitaram Jaswal, Mark Van Schilfgaarde, Ivan I. Oleynik, Derek A. Stewart
Interface Effects In Spin-Dependent Tunneling, Evgeny Y. Tsymbal, Kirill D. Belashchenko, Julian P. Velev, Sitaram Jaswal, Mark Van Schilfgaarde, Ivan I. Oleynik, Derek A. Stewart
Evgeny Tsymbal Publications
In the past few years the phenomenon of spin dependent tunneling (SDT) in magnetic tunnel junctions (MTJs) has aroused enormous interest and has developed into a vigorous field of research. The large tunneling magnetoresistance (TMR) observed in MTJs garnered much attention due to possible application in random access memories and magnetic field sensors. This led to a number of fundamental questions regarding the phenomenon of SDT. One such question is the role of interfaces in MTJs and their effect on the spin polarization of the tunneling current and TMR. In this paper we consider different models which suggest that the …