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Spin-torque oscillator using a perpendicular polarizer and a planar free layer

Nature Materials volume 6, pages 447–453 (2007)Cite this article

Abstract

Spintronics materials have recently been considered for radio-frequency devices such as oscillators by exploiting the transfer of spin angular momentum between a spin-polarized electrical current and the magnetic nanostructure it passes through. While previous spin-transfer oscillators (STOs) were based on in-plane magnetized structures, here we present the realization of an STO that contains a perpendicular spin current polarizer combined with an in-plane magnetized free layer. This device is characterized by high-frequency oscillations of the free-layer magnetization, consistent with out-of-plane steady-state precessions induced at the threshold current by a spin-transfer torque from perpendicularly polarized electrons. The results are summarized in static and dynamic current–field state diagrams and will be of importance for the design of STOs with enhanced output signals.

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Figure 1: Magneto-resistive cell and magneto-resistance.
Figure 2: Macrospin simulations.
Figure 3: Magneto-resistive transfer curve.
Figure 4: Hysteresis loops and static state diagram.
Figure 5: Dynamic spectra and dynamic state diagram.
Figure 6: Dynamic resistance variation.

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Acknowledgements

This work has been supported by the French national programmes ANVAR No A0503013 and ANR/PNANO MagICO No ANR-05-NANO-044, as well as partially by the EC programme DYNAMICS No HPRN-CT-2002-00289. I.F. acknowledges support from the Institut Carnot funding of CEA/LETI. We thank A. Slavin, V. Tiberkevich and C. Baraduc for stimulating discussions, A. Manchon for simulations on the spin polarization and S. Petit for assistance with transport measurements.

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Author notes

  1. M. Brunet

    Present address: Present address: LAAS - CNRS, 7 av du colonel Roche, 31077 Toulouse Cedex 4, France,

  2. D. Houssameddine, U. Ebels and B. Delaët: These authors contributed equally to this work

Authors and Affiliations

  1. SPINTEC URA 2512, C.E.A/DRFMC - C.N.R.S, CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble, France

    D. Houssameddine, U. Ebels, B. Rodmacq, I. Firastrau, C. Thirion, L. Prejbeanu-Buda & B. Dieny

  2. LIMN/DIHS/LETI CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble, France

    B. Delaët, I. Firastrau, F. Ponthenier, M. Brunet, J.-P. Michel, M.-C. Cyrille & O. Redon

  3. Transilvania University of Brasov, 29 Bulevardul Eroilor, R-500036 Brasov, Romania

    I. Firastrau

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Correspondence to U. Ebels or B. Delaët.

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Houssameddine, D., Ebels, U., Delaët, B. et al. Spin-torque oscillator using a perpendicular polarizer and a planar free layer. Nature Mater 6, 447–453 (2007). https://doi.org/10.1038/nmat1905

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