Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

A spin-valve-like magnetoresistance of an antiferromagnet-based tunnel junction

Abstract

A spin valve is a microelectronic device in which high- and low-resistance states are realized by using both the charge and spin of carriers. Spin-valve structures used in modern hard-drive read heads and magnetic random access memoriescomprise two ferromagnetic electrodes whose relative magnetization orientations can be switched between parallel and antiparallel configurations, yielding the desired giant or tunnelling magnetoresistance effect1. Here we demonstrate more than 100% spin-valve-like signal in a NiFe/IrMn/MgO/Pt stack with an antiferromagnet on one side and a non-magnetic metal on the other side of the tunnel barrier. Ferromagneticmoments in NiFe are reversed by external fields of approximately50 mT or less, and the exchange-spring effect2 of NiFe on IrMn induces rotation of antiferromagnetic moments in IrMn, which is detected by the measured tunnelling anisotropic magnetoresistance3. Our work demonstrates a spintronic element whose transport characteristics are governed by an antiferromagnet. It demonstrates that sensitivity to low magnetic fields can be combined with large, spin-orbit-coupling-induced magnetotransport anisotropy using a single magnetic electrode. The antiferromagnetic tunnelling anisotropic magnetoresistance provides a means to study magnetic characteristics of antiferromagnetic films by an electronic-transport measurement.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: A spin-valve-like signal in the NiFe/IrMn(1.5 nm)/MgO/Pt AFM tunnel device compared with the weak magnetoresistance of an FM NiFe/MgO/Pt tunnel junction.
Figure 2: Demonstration of the AFM-TAMR origin of the magnetoresistance of the NiFe/IrMn(1.5 nm)/MgO/Pt stack.
Figure 3: AFM-TAMR in the NiFe/IrMn(3 nm)/MgO/Pt stack.
Figure 4: High-temperature measurements in the NiFe/IrMn/MgO/Pt stacks.

Similar content being viewed by others

References

  1. Chappert, C., Fert, A. & Dau, F. N. V. The emergence of spin electronics in data storage. Nature Mater. 6, 813–823 (2007).

    Article  CAS  Google Scholar 

  2. Scholl, A., Liberati, M., Arenholz, E., Ohldag, H. & Stöhr, J. Creation of an antiferromagnetic exchange spring. Phys. Rev. Lett. 92, 247201 (2004).

    Article  CAS  Google Scholar 

  3. Shick, A. B., Khmelevskyi, S., Mryasov, O. N., Wunderlich, J. & Jungwirth, T. Spin–orbit coupling induced anisotropy effects in bimetallic antiferromagnets: A route towards antiferromagnetic spintronics. Phys. Rev. B 81, 212409 (2010).

    Article  Google Scholar 

  4. Nogués, J. & Schuller, I. K. Exchange bias. J. Magn. Magn. Mater. 192, 203–232 (1999).

    Article  Google Scholar 

  5. Radu, F. & Zabel, H. Exchange bias effect of ferro-/antiferromagnetic heterostructures. Springer Tr. Mod. Phys. 227, 97–184 (2008).

    Article  CAS  Google Scholar 

  6. Núñez, A. S., Duine, R. A., Haney, P. & MacDonald, A. H. Theory of spin torques and giant magnetoresistance in antiferromagnetic metals. Phys. Rev. B 73, 214426 (2006).

    Article  Google Scholar 

  7. Haney, P. M. et al. Ab initio giant magnetoresistance and current-induced torques in Cr/Au/Cr multilayers. Phys. Rev. B 75, 174428 (2007).

    Article  Google Scholar 

  8. Duine, R. A., Haney, P. M., Núñez, A. S. & MacDonald, A. H. Inelastic scattering in ferromagnetic and antiferromagnetic spin valves. Phys. Rev. B 75, 014433 (2007).

    Article  Google Scholar 

  9. Jungwirth, T. et al. Demonstration of molecular beam epitaxy and a semiconducting band structure for I–Mn–V compounds. Phys. Rev. B 83, 035321 (2011).

    Article  Google Scholar 

  10. Gould, C. et al. Tunneling anisotropic magnetoresistance: A spin-valve like tunnel magnetoresistance using a single magnetic layer. Phys. Rev. Lett. 93, 117203 (2004).

    Article  CAS  Google Scholar 

  11. Brey, L., Tejedor, C. & Fernández-Rossier, J. Tunnel magneto-resistance in GaMnAs: Going beyond Jullière formula. Appl. Phys. Lett. 85, 1996–1998 (2004).

    Article  CAS  Google Scholar 

  12. Shick, A. B., Máca, F., Mašek, J. & Jungwirth, T. Prospect for room temperature tunnelling anisotropic magnetoresistance effect: Density of states anisotropies in CoPt systems. Phys. Rev. B 73, 024418 (2006).

    Article  Google Scholar 

  13. Gao, L. et al. Bias voltage dependence of tunneling anisotropic magnetoresistance in magnetic tunnel junctions with MgO and Al2O3 tunnel barriers. Phys. Rev. Lett. 99, 226602 (2007).

    Article  Google Scholar 

  14. Park, B. G. et al. Tunneling anisotropic magnetoresistance in multilayer-(Co/Pt)/AlOx/Pt structures. Phys. Rev. Lett. 100, 087204 (2008).

    Article  CAS  Google Scholar 

  15. Moser, J. et al. Tunneling anisotropic magnetoresistance and spin–orbit coupling in Fe/GaAs/Au tunnel junctions. Phys. Rev. Lett. 100, 056601 (2007).

    Article  Google Scholar 

  16. Wunderlich, J. et al. Coulomb blockade anisotropic magnetoresistance effect in a (Ga,Mn)As single-electron transistor. Phys. Rev. Lett. 97, 077201 (2006).

    Article  CAS  Google Scholar 

  17. Shick, A. B., Máca, F., Ondráček, M., Mryasov, O. N. & Jungwirth, T. Large magnetic anisotropy and tunneling anisotropic magnetoresistance in layered bimetallic nanostructures: Case study of Mn/W(001). Phys. Rev. B 78, 054413 (2008).

    Article  Google Scholar 

Download references

Acknowledgements

We acknowledge support from EU Grant FP7-214499 NAMASTE, FP7-215368 SemiSpinNet, ERC Advanced Grant 268066—0MSPIN and Czech Republic Grants from AV0Z10100521, KAN400100652, LC510 and Preamium Academiae.

Author information

Authors and Affiliations

Authors

Contributions

Device fabrications, Y.K., M.Y., H.Y., A.N., J.H., H.T., B.G.P., J.W.; experiments and data analysis, B.G.P., J.W., X.M., A.B.S., V.H., T.J.; writing, T.J., J.W.; project planning, J.W.,T.J., B.G.P., X.M., A.B.S., J.H., H.T.

Corresponding authors

Correspondence to B. G. Park or T. Jungwirth.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Information (PDF 835 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Park, B., Wunderlich, J., Martí, X. et al. A spin-valve-like magnetoresistance of an antiferromagnet-based tunnel junction. Nature Mater 10, 347–351 (2011). https://doi.org/10.1038/nmat2983

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nmat2983

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing