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.

  • Article
  • Published:

Evidence of intrinsic ferromagnetism in individual dilute magnetic semiconducting nanostructures

Nature Nanotechnology volume 4, pages 523–527 (2009)Cite this article

Abstract

Semiconductors doped with magnetic ions, also known as dilute magnetic semiconductors, are both semiconducting and ferromagnetic. It remains unclear, however, whether this ferromagnetism is intrinsic, as is required for spintronic applications, or is due instead to dopant clustering. Here, we report conclusive evidence for intrinsic ferromagnetism in individual ZnO nanoparticles doped with transition metal ions. Through a simultaneous magnetic and microstructural characterization using electron magnetic chiral dichroism and channelling-enhanced electron energy loss microanalysis, respectively, we show that ZnO nanoparticles have intrinsic ferromagnetism when doped with cobalt, but not when doped with iron.

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

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

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

Figure 1: TEM images and EDS results taken from the cobalt- and iron-doped ZnO samples, disclosing their morphologies, microstructures and chemical compositions.
Figure 2: Dependence of the normalized peak intensities (with respect to that of the O-K edge) of the Zn-L2,3 edge, the Co-L2,3 edge and the Fe-L2,3 edge on the orientation parameter (Δθ).
Figure 3: Typical EMCD results for the cobalt- and iron-doped ZnO samples obtained under the objective lens.
Figure 4: Schematic of the density of states (DOS) of the cobalt- and iron-doped ZnO samples.
Figure 5: EMCD results and the corresponding difference spectra of the cobalt- and iron-doped ZnO samples obtained under the Lorentz lens.

Similar content being viewed by others

References

  1. Wolf, S. A. et al. Spintronics: a spin-based electronics vision for the future. Science 294, 1488–1495 (2001).

    Article  CAS  Google Scholar 

  2. Sharma, P. et al. Ferromagnetism above room temperature in bulk and transparent thin films of Mn-doped ZnO. Nature Mater. 2, 673–677 (2003).

    Article  CAS  Google Scholar 

  3. Kittilstved, K. R., Lin, W. K. & Gamelin, D. R. Electronic structure origins of polarity-dependent high-TC ferromagnetism in oxide-diluted magnetic semiconductors. Nature Mater. 5, 291–297 (2006).

    Article  CAS  Google Scholar 

  4. Radovanovic, P. V. & Gamelin, D. R. High-temperature ferromagnetism in Ni2+-doped aggregates prepared from colloidal diluted magnetic semiconductor quantum dots. Phys. Rev. Lett. 91, 157202 (2003).

    Article  Google Scholar 

  5. Quilty, J. W. et al. Signature of carrier-induced ferromagnetism in Ti1–xCoxO2–δ: exchange interaction between high-spin Co2+ and the Ti 3d conduction band. Phys. Rev. Lett. 96, 027202 (2006).

    Article  CAS  Google Scholar 

  6. Neal, J. R. et al. Room-temperature magneto-optics of ferromagnetic transition-metal- doped ZnO thin films. Phys. Rev. Lett. 96, 197208 (2006).

    Article  CAS  Google Scholar 

  7. Matsukura, F., Ohno, H., Shen, A. & Sugawara, Y. Transport properties and origin of ferromagnetism in (Ga,Mn)As. Phys. Rev. B. 57, R2037–R2040 (1997).

    Article  Google Scholar 

  8. Toyosaki, H. et al. Anomalous Hall effect governed by electron doping in a room-temperature transparent ferromagnetic semiconductor. Nature Mater. 3, 221–224 (2004).

    Article  CAS  Google Scholar 

  9. Shinde, S. R. et al. Co-occurrence of superparamagnetism and anomalous Hall effect in highly reduced cobalt-doped rutile TiO2–δ films. Phys. Rev. Lett. 92, 166601 (2004).

    Article  CAS  Google Scholar 

  10. Xu, Q. Y. et al. Room-temperature ferromagnetism in ZnO films due to defects. Appl. Phys. Lett. 92, 082508 (2008).

    Article  Google Scholar 

  11. Coey, J. M. D., Venkatesan, M. & Fitzgerald, C. B. Donor impurity band exchange in dilute ferromagnetic oxides. Nature Mater. 4, 173–179 (2005).

    Article  CAS  Google Scholar 

  12. Venkatesan, M., Fitzgerald, C. B., Lunney, J. G. & Coey, J. M. D. Anisotropic ferromagnetism in substituted zinc oxide. Phys. Rev. Lett. 93, 177206 (2004).

    Article  CAS  Google Scholar 

  13. Jiang, N. et al. Polarity determination by atomic location by channeling-enhanced microanalysis. Appl. Phys. Lett. 80, 389–391 (2001).

    Article  Google Scholar 

  14. Kong, X., Hu, G. Q., Duan, X. F., Lu, Y. & Liu, X. L. Polarity determination for GaN thin films by electron energy-loss spectroscopy. Appl. Phys. Lett. 81, 1990–1992 (2002).

    Article  CAS  Google Scholar 

  15. Liu, Y. Z. et al. Co location and valence state determination in ferromagnetic ZnO:Co thin films by atom-location-by-channeling-enhanced-microanalysis electron energy-loss spectroscopy. Appl. Phys. Lett. 90, 154101 (2007).

    Article  Google Scholar 

  16. Wang, X. F. et al. Signature of intrinsic high-temperature ferromagnetism in cobalt-doped zinc oxide nanocrystals. Adv. Mater. 18, 2476–2480 (2006).

    Article  CAS  Google Scholar 

  17. Hébert, C. & Schattschneider, P. A proposal for dichroic experiments in the electron microscope. Ultramicroscopy 96, 463–468 (2003).

    Article  Google Scholar 

  18. Schattschneider, P. et al. Detection of magnetic circular dichroism using a transmission electron microscope. Nature 441, 486–488 (2006).

    Article  CAS  Google Scholar 

  19. Stöhr, J. Exploring the microscopic origin of magnetic anisotropies with X-ray magnetic circular dichroism (XMCD) spectroscopy. J. Magn. Magn. Mater. 200, 470–497 (1999).

    Article  Google Scholar 

  20. Egerton, R. F. Electron Energy Loss Spectroscopy in the Electron Microscope 2nd edn (Plenum Press, 1996).

    Book  Google Scholar 

  21. Kittel, C. Introduction to Solid States Physics 7th edn (Wiley, 1996).

    Google Scholar 

  22. Muller, S., Zhou, M. J., Li, Q. & Ronning, C. Intra-shell luminescence of transition-metal-implanted zinc oxide nanowires. Nanotechnology 20, 135704 (2009).

    Article  Google Scholar 

  23. Schattschneider, P. et al. Magnetic circular dichroism in EELS: Towards 10 nm resolution. Ultramicroscopy 108, 433–438 (2008).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

The authors are grateful to X.F. Duan and R.C. Che for the use of the Lorentz microscope, and B. Zhang and X.X. Zhang for the SQUID measurements. Q.L. thanks H.Q. Lin and L.J. Sham for stimulating discussions and valuable suggestions. This work was supported by grants from the RGC of Hong Kong (CUHK 402007 and N_CUHK447/07), UGC SEG (CUHK06), CUHK Focused Investments Scheme C and DFG of the Priority Program 1165 (1198/7-3).

Author information

Authors and Affiliations

  1. Department of Physics, The Chinese University of Hong Kong, Shatin, New Territory, Hong Kong SAR, China

    Z. H. Zhang & Quan Li

  2. Department of Electronic Engineering and Materials Science and Technology Research Center, The Chinese University of Hong Kong, Shatin, New Territory, Hong Kong SAR, China

    Xuefeng Wang & J. B. Xu

  3. Institute of Physics, University of Gottingen, Friedrich-Hund-Platz 1, Gottingen, 37077, Germany

    S. Muller

  4. Institute of Solid State Physics, University of Jena, Max-Wien-Platz 1, Jena, 07743, Germany

    C. Ronning

  5. Liaoning Key Materials Laboratory for Railway, DaLian JiaoTong University, DaLian, China

    Z. H. Zhang

  6. Department of Physics, Soochow University, Suzhou, 215006, China

    Xuefeng Wang

Authors
  1. Z. H. Zhang
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Xuefeng Wang
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. J. B. Xu
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. S. Muller
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. C. Ronning
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Quan Li
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

Z.H.Z. and Q.L. conceived and designed the experiments, analysed the data and co-wrote the paper. Z.H.Z. performed the electron microscopy experiments. S.M. contributed iron-doped materials and X.F.W. contributed cobalt-doped ZnO materials. S.M., X.F.W., C.R. and J.B.X. performed the magnetic and optical characterizations on a macroscopic scale and analysed the data. All authors discussed the results and commented on the manuscript.

Corresponding author

Correspondence to Quan Li.

Supplementary information

Supplementary information

Supplementary information (PDF 2069 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Zhang, Z., Wang, X., Xu, J. et al. Evidence of intrinsic ferromagnetism in individual dilute magnetic semiconducting nanostructures. Nature Nanotech 4, 523–527 (2009). https://doi.org/10.1038/nnano.2009.181

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nnano.2009.181

This article is cited by

Search

Advanced 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