Role of Metal-Oxide Interface in Determining the Spin Polarization of Magnetic Tunnel Junctions

Teresa, J. M. De; Barthélémy, A.; Fert, A.; Contour, J. P.; Montaigne, F.; Sénéor, Pierre

doi:10.1126/science.286.5439.507

Cited by 588 publications

(386 citation statements)

References 13 publications

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“…5 For spin-transport processes it is interface rather than bulk properties that are of essential importance, because the TMR ratio is sensitive to the interfaces. 6 Off-stoichiometry of the Heusler alloys is also expected to profoundly influence the half-metallic ferromagnetism and hence the TMR characteristic. The effect of defects in the Heusler alloys Co 2 Y Z introduced by off-stoichiometry on the spin-dependent electronic structure has been investigated theoretically [7][8][9][10][11][12] as well as experimentally.…”

Section: Introductionmentioning

confidence: 99%

Effects of off-stoichiometry on the spin polarization at the Co2MnβGe0.38/MgO interfa

et al. 2012

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We have studied the electronic and magnetic states of Mn and Co atoms at the Co 2 Mn β Ge 0.38 (CMG)/MgO (β = 0.67-1.8) interfaces, which constitute CMG/MgO/CMG magnetic tunnel junctions, by means of x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroisms (XMCDs) at the Mn and Co L 2,3 edges and compared the deduced Co and Mn magnetic moments by the density-functional calculations with the coherent potential approximation (CPA). As the Mn content β increased, the intensity of Mn L 2,3 XMCD decreased, in agreement with the result of the CPA calculation, which showed the resultant reduction of charges and spin moment on Mn atoms because of the delocalization of Mn 3d electrons with increasing β. The Co spin magnetic moment for all the samples increased with decreasing β, again consistent with the present calculation and the previous density-functional calculation by Picozzi et al. that the Co Mn antisite has a larger magnetic moment than that of Co atoms at the regular sites and reduces the spin polarization at the Fermi level and hence the tunnel magnetoresistance ratio.

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Section: Introductionmentioning

confidence: 99%

Effects of off-stoichiometry on the spin polarization at the Co2MnβGe0.38/MgO interfa

et al. 2012

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“…large dielectric constant and height barrier for electron tunneling), aluminum oxides are promising candidate for gate dielectrics in the nanoscale CMOS technology, magnetic tunneling junctions, magnetic sensors, magnetic storage devices and solid-state memory, etc. [1][2][3]. At the same time, significant progress has been made to understand the combustion of nano-aluminum powders and the highly exothermic reaction of fine-grained aluminum particles (size < 100 nm) with oxygen because of their use as potential additives to propellants for rockets [4][5][6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

“…At the same time, significant progress has been made to understand the combustion of nano-aluminum powders and the highly exothermic reaction of fine-grained aluminum particles (size < 100 nm) with oxygen because of their use as potential additives to propellants for rockets [4][5][6][7][8][9]. For all these applications, it is crucial to understand the physico-chemical processes which control the reactivity of the metallic substrate and the thickness, morphology, chemical composition and microstructure of the oxide film [1].…”

Section: Introductionmentioning

confidence: 99%

Oxidation of nanocrystalline aluminum by variable charge molecular dynamics

Perron

Garruchet

Politano

et al. 2010

Journal of Physics and Chemistry of Solids

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We investigate the oxidation of nanocrystalline aluminum surfaces using molecular dynamics (MD) simulations with the variable charge model that allows charge dynamically transfer among atoms. The interaction potential between atoms is described by the electrostatic plus (Es+) potential model, which is composed of an embedded atom method potential and an electrostatic term. The simulations were performed from 300 to 750K on polycrystalline samples with a mean grain size of 5 nanometers. We mainly focused on the effect of the temperature parameter on the oxidation kinetic. The results show that, beyond a first linear regime, the kinetics follow a direct logarithmic law (governed by diffusion process) and tend to a limiting value corresponding to a thickness of ~3nm. We also characterized at 600K the effects of an external applied strain on the microstructure and the chemical composition of the oxide films formed at the surface. In particular, we obtained a partially crystalline oxide films for all temperature and we noticed a strong correlation between the degree of crystallinity of the oxide film and the oxidation temperature.

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“…Various approaches have been explored in order to enhance the TMR value, for example, incorporate half-metallic electrodes for their near ideal spin polarizations [3,4,5], to construct epitaxial MgO barriers coupled with bcc-ferromagnets for the establishment of coherent tunneling [6,7,8,9], or to take advantage of magnetic insulators for their spin-filter capabilities [ 10 , 11 , 12,13 ]. Tremendous progress has been made with these approaches for the purpose of generating and enhancing TMR [14].…”

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confidence: 99%