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Articles 1 - 6 of 6
Full-Text Articles in Physical Sciences and Mathematics
Effect Of Disorder On Perpendicular Magnetotransport In Co/Cu Multilayers, Evgeny Y. Tsymbal
Effect Of Disorder On Perpendicular Magnetotransport In Co/Cu Multilayers, Evgeny Y. Tsymbal
Evgeny Tsymbal Publications
We investigate the spin-dependent conductance of the Co/Cu multilayers in the current-perpendicular-tothe- plane (CPP) geometry. Using a realistic tight-binding model for the electronic band structure of the multilayer, and introducing disorder in the on-site atomic energies we calculate the conductance and giant magnetoresistance (GMR) within the quantum-mechanical linear response theory by performing averaging over random disorder configurations. By varying the thickness and the number of individual layers and the degree of disorder in the multilayers, we analyze factors influencing the CPP GMR. In particular, we show the importance of the thickness-dependent interface resistance, which depends on the mean free path …
Theory Of Magnetostatic Coupling In Thin-Film Rectangular Magnetic Elements, Evgeny Y. Tsymbal
Theory Of Magnetostatic Coupling In Thin-Film Rectangular Magnetic Elements, Evgeny Y. Tsymbal
Evgeny Tsymbal Publications
A theory of magnetostatic coupling in thin-film uniformly magnetized arrays of rectangular magnetic elements is presented. Analytic expressions for the magnetostatic energy and the dipolar fields are derived. The influence of the aspect ratio and the spacing between the elements on the magnetostatic coupling is investigated. It is found that increasing the aspect ratio reduces the critical distance between the elements, above which the magnetostatic inter-element coupling can be neglected.
Oxygen-Induced Positive Spin Polarization From Fe In The Vacuum Barrier, Evgeny Y. Tsymbal, Ivan I. Oleinik, David G. Pettifor
Oxygen-Induced Positive Spin Polarization From Fe In The Vacuum Barrier, Evgeny Y. Tsymbal, Ivan I. Oleinik, David G. Pettifor
Evgeny Tsymbal Publications
Bonding at the ferromagnet–insulator interface is an important factor which influences spin polarization of the tunneling current in ferromagnetic tunnel junctions. In this article we investigate the spin-polarized electronic structure of the (001) surface of body-centered-cubic iron covered by an oxygen overlayer, as this could reflect the mechanism of bonding and spin polarization in iron/oxide tunnel junctions. The Fe/O atomic structure is optimized using the plane-wave code CASTEP within the spin-polarized generalized-gradient approximation. The electronic structure and local densities of states are calculated using the linear muffin-tin orbital method. The results show hybridization of the iron 3d orbitals with …
Structural And Electronic Properties Of Cobalt/Alumina Tunnel Junctions From First Principles, Ivan I. Oleinik, Evgeny Y. Tsymbal, David G. Pettifor
Structural And Electronic Properties Of Cobalt/Alumina Tunnel Junctions From First Principles, Ivan I. Oleinik, Evgeny Y. Tsymbal, David G. Pettifor
Evgeny Tsymbal Publications
A detailed first-principles study of the atomic and electronic structure of the Co/Al2O3/Co magnetic tunnel junction has been performed in order to elucidate the key features determining the spin-dependent tunneling. The atomic structure of the multilayer with the O- and Al-terminated interfaces between fcc Co(111) and crystalline α-Al2O3(0001) has been optimized using self-consistent spin-polarized calculations within densityfunctional theory and the generalized gradient approximation. We found that the relaxed atomic structure of the O-terminated interface is characterized by a rippling of the Co interfacial plane, the average Co-O bond length being 2.04 Å …
Electronic Scattering From Co/Cu Interfaces: In-Situ Measurement And Comparison With Theory, W. E. Bailey, Shan X. Wang, Evgeny Y. Tsymbal
Electronic Scattering From Co/Cu Interfaces: In-Situ Measurement And Comparison With Theory, W. E. Bailey, Shan X. Wang, Evgeny Y. Tsymbal
Evgeny Tsymbal Publications
The full thickness-dependent electrical conductivity of polycrystalline NiO/Co/Cu/Co spin-valve structures was measured in situ during ion-beam deposition and compared with calculations based on realistic band structure. We have found striking features in the experimental conductivity which are unexpected from widely used semiclassical free-electron models. Addition of ∼ 1 ML Co to a NiO/Co/Cu surface causes the net film conductance to decrease; the reverse case of Cu on NiO/Co shows a strong positive curvature of the thicknessdependent conductance, indicating a reduction of the conductivity in Cu near the interface with Co. Quantitative agreement is found between the experimental thickness-dependent film conductance …
Quantum-Well Resistivity For Perpendicular Transport In Magnetic Layered Systems, Evgeny Y. Tsymbal, David G. Pettifor
Quantum-Well Resistivity For Perpendicular Transport In Magnetic Layered Systems, Evgeny Y. Tsymbal, David G. Pettifor
Evgeny Tsymbal Publications
We show that quantum-well states enhance the current-perpendicular-to-planes resistivity of a metal film compared to the resistivity in the bulk at film thicknesses comparable with the mean free path due to the reduced number of conducting channels within the potential-well structure. This makes the mean free path an important parameter, which must be taken into account for the accurate treatment of results on currentperpendicular- to-plane giant magnetoresistance, rather than ignored by applying the two-current series-resistor model.