Effect of the interface resistance of CoFe/MgO contacts on spin accumulation in silicon

Ishikawa, M.; Sugiyama, H.; Inokuchi, T.; Hamaya, Kohei; Saito, Y.

doi:10.1063/1.4728117

Cited by 51 publications

(59 citation statements)

References 29 publications

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“…However, in the previous studies, most of them are focused on the tunnel materials selection and interface properties between magnetic electrodes and semiconductors [6][7][8][9][10][11][12][13][14] with relatively high spin polarization magnetic metal electrodes, such as Fe [4], CoFe [15] and NiFe [16,17]. In fact, the properties of the magnetic metal thin films, applied as electrodes, should have a significant effect on the spin injection efficiency [18].…”

Section: Introductionmentioning

confidence: 97%

Thermal annealing and magnetic anisotropy of NiFe thin films on n+-Si for spintronic device applications

Lü

Huang

Wang

et al. 2015

Journal of Magnetism and Magnetic Materials

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Section: Introductionmentioning

confidence: 97%

Thermal annealing and magnetic anisotropy of NiFe thin films on n+-Si for spintronic device applications

Lü

Huang

Wang

et al. 2015

Journal of Magnetism and Magnetic Materials

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“…To create and detect spin-polarized carriers in nonmagnetic materials, the use of ferromagnetic tunnel contacts has proven to be a robust and technologically viable approach that is widely used in spin-based devices, including those with Si and Ge [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. As recently reviewed [4,25], controversy has arisen because in many semiconductor spintronic devices, the magnitude of the observed spin voltage differs by several orders of magnitude from what is expected based on the available theory for spin injection and diffusion [26][27][28][29].…”

Section: Introductionmentioning

confidence: 99%

Anomalous scaling of spin accumulation in ferromagnetic tunnel devices with silicon and germanium

et al. 2014

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Anomalous scaling of spin accumulation in ferromagnetic tunnel devices with silicon and germanium Sharma, S.; Spiesser, A.; Dash, S.P.; Iba, S.; Watanabe, S.; Wees, B.J. van; Saito, H.; Yuasa, S.; Jansen, R. Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. The magnitude of spin accumulation created in semiconductors by electrical injection of spin-polarized electrons from a ferromagnetic tunnel contact is investigated, focusing on how the spin signal detected in a Hanle measurement varies with the thickness of the tunnel oxide. An extensive set of spin-transport data for Si and Ge magnetic tunnel devices reveals a scaling with the tunnel resistance that violates the core feature of available theories, namely, the linear proportionality of the spin voltage to the injected spin current density. Instead, an anomalous scaling of the spin signal with the tunnel resistance is observed, following a power law with an exponent between 0.75 and 1 over 6 decades. The scaling extends to tunnel resistance values larger than 10 9 μm 2 , far beyond the regime where the classical impedance mismatch or back flow into the ferromagnet play a role. This scaling is incompatible with existing theory for direct tunnel injection of spins into the semiconductor. It also demonstrates conclusively that the large spin signal does not originate from two-step tunneling via localized states near the oxide/semiconductor interface. Control experiments show that spin accumulation in localized states within the tunnel barrier or artifacts are also not responsible. Altogether, the scaling results suggest that, contrary to all existing descriptions, the spin signal is proportional to the applied bias voltage, rather than the (spin) current.

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“…(1) can no longer be used to describe the measured spin signal when the detector is biased, as in the case of the 3T method. This aspect of the 3T spin detection was hitherto not taken into account, although some experiments on Si devices show correlation between measured spin signals and tunnel resistance [36,37] or differential resistance [38] of the junction. Although our experiments were conducted on spin Esaki diode devices, we find the results are quite general.…”

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confidence: 99%

Giant enhancement of spin detection sensitivity in (Ga,Mn)As/GaAs Esaki diodes

et al. 2014

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We investigate the correlation between spin signals measured in three-terminal (3T) geometry by the Hanle effect and the spin accumulation generated in a semiconductor channel in a lateral (Ga,Mn)As/GaAs Esaki diode device. We systematically compare measurements using a 3T configuration, probing spin accumulation directly beneath the injecting contact, with results from nonlocal measurements, where solely spin accumulation in the GaAs channel is probed. We find that the spin signal detected in the 3T configuration is dominated by a bias-dependent spin detection sensitivity, which in turn is strongly correlated with charge-transport properties of the junction. This results in a particularly strong enhancement of the detected spin signal in a region of increased differential resistance. We find additionally that two-step tunneling via localized states in the gap of (Ga,Mn)As does not compromise spin injection into the semiconductor conduction band.

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Effect of the interface resistance of CoFe/MgO contacts on spin accumulation in silicon

Cited by 51 publications

References 29 publications

Thermal annealing and magnetic anisotropy of NiFe thin films on n+-Si for spintronic device applications

Thermal annealing and magnetic anisotropy of NiFe thin films on n+-Si for spintronic device applications

Anomalous scaling of spin accumulation in ferromagnetic tunnel devices with silicon and germanium

Giant enhancement of spin detection sensitivity in (Ga,Mn)As/GaAs Esaki diodes

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