Crossovers from in-plane to perpendicular anisotropy in magnetic tunnel junctions as a function of the barrier degree of oxidation

Rodmacq, B.; Auffret, S.; Diény, B.; Monso, S.; Boyer, P.

doi:10.1063/1.1555292

Cited by 64 publications

(70 citation statements)

References 7 publications

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“…A magnetic coupling at the electrode interface also exists in other common material combinations like AlOx-Co [37,38]. This needs to be considered when using the electrode rotation technique to determine the spin-lifetime anisotropy.…”

Section: A Rotating the Electrode Magnetizationmentioning

confidence: 99%

Measuring anisotropic spin relaxation in graphene

et al. 2018

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We compare different methods to measure the anisotropy of the spin lifetime in graphene. In addition to out-of-plane rotation of the ferromagnetic electrodes and oblique spin precession, we present a Hanle experiment where the electron spins precess around either a magnetic field perpendicular to the graphene plane or around an in-plane field. In the latter case, electrons are subject to both in-plane and out-of-plane spin relaxation. To fit the data, we use a numerical simulation that can calculate precession with anisotropies in the spin lifetimes under magnetic fields in any direction. Our data show a small, but distinct anisotropy that can be explained by the combined action of isotropic mechanisms, such as relaxation by the contacts and resonant scattering by magnetic impurities, and an anisotropic Rashba spin-orbit based mechanism. We also assess potential sources of error in all three types of experiment and conclude that the in-plane/out-of-plane Hanle method is most reliable.

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Section: A Rotating the Electrode Magnetizationmentioning

confidence: 99%

Measuring anisotropic spin relaxation in graphene

et al. 2018

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“…Fully perpendicular magnetic tunnel junctions (pMTJ) constitute the storage element of spin-transfer torque magnetoresistive random access memory (STT-MRAM) [1][2][3][4][5][6]. STTMRAMs are very promising emerging nonvolatile memories since they combine nonvolatility, low energy consumption, high thermal stability, and almost unlimited endurance.…”

Section: Introductionmentioning

confidence: 99%

Respective influence of in-plane and out-of-plane spin-transfer torques in magnetization switching of perpendicular magnetic tunnel junctions

et al. 2015

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International audienceThe relative contributions of in-plane (damping-like) and out-of-plane (field-like) spin-transfer torques (STT) in the magnetization switching of out-of-plane magnetized magnetic tunnel junctions (pMTJ) has been theoretically analyzed using the transformed Landau-Lifshitz-Gilbert (LLG) equation with the STT terms. It is demonstrated that in a pMTJ structure obeying macrospin dynamics, the out-of-plane torque influences the precession frequency, but it does not contribute significantly to the STT switching process (in particular to the switching time and switching current density), which is mostly determined by the in-plane STT contribution. This conclusion is confirmed by finite temperature and finite writing pulse macrospin simulations of the current field switching diagrams. It contrasts with the case of STT switching in in-plane magnetized magnetic tunnel junction (MTJ) in which the field-like term also influences the switching critical current. This theoretical analysis was successfully applied to the interpretation of voltage field STT switching diagrams experimentally measured on pMTJ pillars 36 nm in diameter, which exhibit macrospin behavior. The physical nonequivalence of Landau and Gilbert dissipation terms in the presence of STT-induced dynamics is also discussed

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“…It is worth mentioning here that perpendicular magnetic anisotropy has been reported, both theoretically and experimentally, in the Fe/MgO system [39], but it has also been shown that it strongly depends on the oxidation degree of interfaces [40,41]. In addition, AF coupling due to interlayer exchange coupling has also been reported for the Fe/MgO/Fe system for MgO barrier thicknesses around 1 nm [42].…”

Section: Resultsmentioning

confidence: 89%

Interfacial effects on the tunneling magnetoresistance inLa0.7Sr0.3MnO3/<

et al. 2015

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We report on magnetotransport properties on La 0.7 Sr 0.3 MnO 3 /MgO/Fe tunnel junctions grown epitaxially on top of (001)-oriented SrTiO 3 substrates by sputtering. It is shown that the magnetoresistive response depends critically on the MgO/Fe interfacial properties. The appearance of an FeO X layer by the interface destroys the 1 symmetry filtering effect of the MgO/Fe system and only a small negative tunneling magnetoresistance (TMR) (∼ −3 %) is measured. However, in annealed samples a switchover from positive TMR (∼ +25% at 70 K) to negative TMR (∼ −1 %) is observed around 120 K. This change is associated with the transition from semiconducting at high T to insulating at low T taking place at the Verwey transition (T V ∼ 120 K) in Fe 3 O 4 , thus suggesting the formation of a very thin slab of magnetite at the MgO/Fe interface during annealing treatments. These results highlight the relevance of interfacial properties on the tunneling conduction process and how it can be substantially modified through appropriate interface engineering.

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Crossovers from in-plane to perpendicular anisotropy in magnetic tunnel junctions as a function of the barrier degree of oxidation

Cited by 64 publications

References 7 publications

Measuring anisotropic spin relaxation in graphene

Measuring anisotropic spin relaxation in graphene

Respective influence of in-plane and out-of-plane spin-transfer torques in magnetization switching of perpendicular magnetic tunnel junctions

Interfacial effects on the tunneling magnetoresistance inLa0.7Sr0.3MnO3/<

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