The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform
S Mangin - One of the best experts on this subject based on the ideXlab platform.
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Magnetoresistive effects in perpendicularly magnetized Tb-Co alloy based thin films and spin valves
Journal of Applied Physics, 2012Co-Authors: M. Gottwald, F Montaigne, M. Hehn, D. Lacour, G. Lengaigne, S Suire, S ManginAbstract:Tb-Co ferrimagnetic alloy thin films and spin valves have been grown to study their Magnetoresistance response in various geometries. The studied Tb-Co alloys show strong perpendicular anisotropy and tunable magnetization by several orders of magnitude. Magnetoresistance signals such as giant Magnetoresistance (GMR), anisotropic Magnetoresistance (AMR), extraordinary Hall effect (EHE), and magnon Magnetoresistance (MMR) have been studied. The angular dependence of those magnetoresistive effects is also investigated. Finally we demonstrate that by adjusting the Tb-Co layer composition in a spin valve structure, the sign and the amplitude of the GMR and EHE signal can be tuned.
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Influence of an interface domain wall on spin-valve giant Magnetoresistance
Applied Physics Letters, 2008Co-Authors: Thomas Hauet, F Montaigne, M. Hehn, Y Henry, S ManginAbstract:The magnetotransport properties of a Gd 40 Fe 60 / Gd 10 Fe 90 / Cu/ Gd 40 Fe 60 spin-valve based on amorphous ferrimagnetic GdFe layers are reported. The Gd 40 Fe 60 / Gd 10 Fe 90 bilayer is an exchange spring structure that allows an interfacial domain wall to be controlled by an applied field. As this domain wall is nucleated, compressed, and annihilated, changes in the spin-valve current-in-plane Magnetoresistance are observed. After separating the various Magnetoresistance contributions we could deduce the effect of the interface domain wall on both the giant and anisotropic Magnetoresistances. Several architectures have been used to attain a better understanding of giant Magnetoresistance ͑GMR͒ phenomenon. This important activity has been driven by its strong implications for magnetic data storage devices and sensors. 1 In most GMR structures, the magnetic electrodes are sufficiently thin so that the magnetization could be considered as uniform across the thickness of the ferromagnetic layers. However, it is commonly known that GMR originates from a combination of interfacial and bulk spin-dependent scattering. Therefore, one may expect that a vertically nonuniform magnetization state of the magnetic layer would reflect in its GMR response. One way to induce a perpendicular-to-layer nonuniform magnetic configuration in a spin valve consists in replacing one of the magnetic electrodes with an exchange-coupled bilayer system. 2–4 in which a planar interface domain wall ͑iDW͒ may be tuned. In the present letter, we report on the Magnetoresistance properties of such a modified spin-valve structure, Gd 40 Fe 60 / Gd 10 Fe 90 / Cu/ Gd 40 Fe 60 , where Gd x Fe 1−x are ferri-magnetic alloys. The alloys' magnetic properties ͑magnetiza-tion, anisotropy, exchange stiffness, etc.͒ can easily be tuned by changing composition 5 and/or growth conditions. 6 Such materials have already been used in spin-valve structures 7,8
Mahmoud Eddrief - One of the best experts on this subject based on the ideXlab platform.
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Magnetoresistance in granular magnetic tunnel junctions with Fe nanoparticles embedded in ZnSe semiconducting epilayer
Journal of Applied Physics, 2008Co-Authors: A.r. De Moraes, C.k. Saul, D.h. Mosca, J. Varalda, P. Schio, A.j.a. De Oliveira, M.a. Canesqui, V. Garcia, Dominique Demaille, Mahmoud EddriefAbstract:We have investigated transport properties of iron (Fe) nanoparticles embedded in zinc selenide (ZnSe) semiconducting epilayers prepared by molecular beam epitaxy. Both positive and negative tunneling Magnetoresistances (TMRs) were measured depending on the applied voltage biases and on the temperature. A slow reduction of the TMR magnitude with temperature was detected and it could be explained in terms of a crossover between direct/resonant tunneling and variable range hopping. The temperature behavior of the Magnetoresistance is a clear signature of tunneling and hopping mechanisms mediated by the ZnSe barrier localized states.
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Magnetoresistance in granular magnetic tunnel junctions with Fe nanoparticles embedded in ZnSe semiconducting epilayer
Journal of Applied Physics, 2008Co-Authors: A.r. De Moraes, C.k. Saul, D.h. Mosca, J. Varalda, P. Schio, A.j.a. De Oliveira, M.a. Canesqui, V. Garcia, Dominique Demaille, Mahmoud EddriefAbstract:We have investigated transport properties of iron (Fe) nanoparticles embedded in zinc selenide (ZnSe) semiconducting epilayers prepared by molecular beam epitaxy. Both positive and negative tunneling Magnetoresistances (TMRs) were measured depending on the applied voltage biases and on the temperature. A slow reduction of the TMR magnitude with temperature was detected and it could be explained in terms of a crossover between direct/resonant tunneling and variable range hopping. The temperature behavior of the Magnetoresistance is a clear signature of tunneling and hopping mechanisms mediated by the ZnSe barrier localized states. (C) 2008 American Institute of Physics.
A.r. De Moraes - One of the best experts on this subject based on the ideXlab platform.
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Magnetoresistance in granular magnetic tunnel junctions with Fe nanoparticles embedded in ZnSe semiconducting epilayer
Journal of Applied Physics, 2008Co-Authors: A.r. De Moraes, C.k. Saul, D.h. Mosca, J. Varalda, P. Schio, A.j.a. De Oliveira, M.a. Canesqui, V. Garcia, Dominique Demaille, Mahmoud EddriefAbstract:We have investigated transport properties of iron (Fe) nanoparticles embedded in zinc selenide (ZnSe) semiconducting epilayers prepared by molecular beam epitaxy. Both positive and negative tunneling Magnetoresistances (TMRs) were measured depending on the applied voltage biases and on the temperature. A slow reduction of the TMR magnitude with temperature was detected and it could be explained in terms of a crossover between direct/resonant tunneling and variable range hopping. The temperature behavior of the Magnetoresistance is a clear signature of tunneling and hopping mechanisms mediated by the ZnSe barrier localized states.
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Magnetoresistance in granular magnetic tunnel junctions with Fe nanoparticles embedded in ZnSe semiconducting epilayer
Journal of Applied Physics, 2008Co-Authors: A.r. De Moraes, C.k. Saul, D.h. Mosca, J. Varalda, P. Schio, A.j.a. De Oliveira, M.a. Canesqui, V. Garcia, Dominique Demaille, Mahmoud EddriefAbstract:We have investigated transport properties of iron (Fe) nanoparticles embedded in zinc selenide (ZnSe) semiconducting epilayers prepared by molecular beam epitaxy. Both positive and negative tunneling Magnetoresistances (TMRs) were measured depending on the applied voltage biases and on the temperature. A slow reduction of the TMR magnitude with temperature was detected and it could be explained in terms of a crossover between direct/resonant tunneling and variable range hopping. The temperature behavior of the Magnetoresistance is a clear signature of tunneling and hopping mechanisms mediated by the ZnSe barrier localized states. (C) 2008 American Institute of Physics.
Jing Shi - One of the best experts on this subject based on the ideXlab platform.
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giant Magnetoresistance in organic spin valves
Nature, 2004Co-Authors: Z H Xiong, Valy Z Vardeny, Jing ShiAbstract:A spin valve is a layered structure of magnetic and non-magnetic (spacer) materials whose electrical resistance depends on the spin state of electrons passing through the device and so can be controlled by an external magnetic field. The discoveries of giant Magnetoresistance1 and tunnelling Magnetoresistance2 in metallic spin valves have revolutionized applications such as magnetic recording and memory, and launched the new field of spin electronics3—‘spintronics’. Intense research efforts are now devoted to extending these spin-dependent effects to semiconductor materials. But while there have been noteworthy advances in spin injection and detection using inorganic semiconductors4,5,6, spin-valve devices with semiconducting spacers have not yet been demonstrated. π-conjugated organic semiconductors may offer a promising alternative approach to semiconductor spintronics, by virtue of their relatively strong electron–phonon coupling7 and large spin coherence8. Here we report the injection, transport and detection of spin-polarized carriers using an organic semiconductor as the spacer layer in a spin-valve structure, yielding low-temperature giant Magnetoresistance effects as large as 40 per cent.
M. Hehn - One of the best experts on this subject based on the ideXlab platform.
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Magnetoresistive effects in perpendicularly magnetized Tb-Co alloy based thin films and spin valves
Journal of Applied Physics, 2012Co-Authors: M. Gottwald, F Montaigne, M. Hehn, D. Lacour, G. Lengaigne, S Suire, S ManginAbstract:Tb-Co ferrimagnetic alloy thin films and spin valves have been grown to study their Magnetoresistance response in various geometries. The studied Tb-Co alloys show strong perpendicular anisotropy and tunable magnetization by several orders of magnitude. Magnetoresistance signals such as giant Magnetoresistance (GMR), anisotropic Magnetoresistance (AMR), extraordinary Hall effect (EHE), and magnon Magnetoresistance (MMR) have been studied. The angular dependence of those magnetoresistive effects is also investigated. Finally we demonstrate that by adjusting the Tb-Co layer composition in a spin valve structure, the sign and the amplitude of the GMR and EHE signal can be tuned.
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Influence of an interface domain wall on spin-valve giant Magnetoresistance
Applied Physics Letters, 2008Co-Authors: Thomas Hauet, F Montaigne, M. Hehn, Y Henry, S ManginAbstract:The magnetotransport properties of a Gd 40 Fe 60 / Gd 10 Fe 90 / Cu/ Gd 40 Fe 60 spin-valve based on amorphous ferrimagnetic GdFe layers are reported. The Gd 40 Fe 60 / Gd 10 Fe 90 bilayer is an exchange spring structure that allows an interfacial domain wall to be controlled by an applied field. As this domain wall is nucleated, compressed, and annihilated, changes in the spin-valve current-in-plane Magnetoresistance are observed. After separating the various Magnetoresistance contributions we could deduce the effect of the interface domain wall on both the giant and anisotropic Magnetoresistances. Several architectures have been used to attain a better understanding of giant Magnetoresistance ͑GMR͒ phenomenon. This important activity has been driven by its strong implications for magnetic data storage devices and sensors. 1 In most GMR structures, the magnetic electrodes are sufficiently thin so that the magnetization could be considered as uniform across the thickness of the ferromagnetic layers. However, it is commonly known that GMR originates from a combination of interfacial and bulk spin-dependent scattering. Therefore, one may expect that a vertically nonuniform magnetization state of the magnetic layer would reflect in its GMR response. One way to induce a perpendicular-to-layer nonuniform magnetic configuration in a spin valve consists in replacing one of the magnetic electrodes with an exchange-coupled bilayer system. 2–4 in which a planar interface domain wall ͑iDW͒ may be tuned. In the present letter, we report on the Magnetoresistance properties of such a modified spin-valve structure, Gd 40 Fe 60 / Gd 10 Fe 90 / Cu/ Gd 40 Fe 60 , where Gd x Fe 1−x are ferri-magnetic alloys. The alloys' magnetic properties ͑magnetiza-tion, anisotropy, exchange stiffness, etc.͒ can easily be tuned by changing composition 5 and/or growth conditions. 6 Such materials have already been used in spin-valve structures 7,8
