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:

Bulk electronic structure of the dilute magnetic semiconductor Ga1−xMnxAs through hard X-ray angle-resolved photoemission

Abstract

A detailed understanding of the origin of the magnetism in dilute magnetic semiconductors is crucial to their development for applications. Using hard X-ray angle-resolved photoemission (HARPES) at 3.2 keV, we investigate the bulk electronic structure of the prototypical dilute magnetic semiconductor Ga0.97Mn0.03As, and the reference undoped GaAs. The data are compared to theory based on the coherent potential approximation and fully relativistic one-step-model photoemission calculations including matrix-element effects. Distinct differences are found between angle-resolved, as well as angle-integrated, valence spectra of Ga0.97Mn0.03As and GaAs, and these are in good agreement with theory. Direct observation of Mn-induced states between the GaAs valence-band maximum and the Fermi level, centred about 400 meV below this level, as well as changes throughout the full valence-level energy range, indicates that ferromagnetism in Ga1−xMnxAs must be considered to arise from both pd exchange and double exchange, thus providing a more unifying picture of this controversial material.

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

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

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

Figure 1: HARPES measurements and one-step theory for bulk GaAs and Ga0.97Mn0.03As.
Figure 2: One-step theory spectral functions for GaAs and Ga0.97Mn0.03As.
Figure 3: Angle-integrated valence-band spectra for GaAs and Ga0.97Mn0.03As.
Figure 4: Analysis of the near-Fermi-edge region in the HARPES data.
Figure 5: GaAs and Ga0.97Mn0.03 As theoretical DOS.

Similar content being viewed by others

References

  1. Ohno, H. et al. (Ga,Mn)As: A new diluted magnetic semiconductor based on GaAs. Appl. Phys. Lett. 69, 363–365 (1996).

    Article  CAS  Google Scholar 

  2. Ohno, H. Making nonmagnetic semiconductors ferromagnetic. Science 281, 951–956 (1998).

    Article  CAS  Google Scholar 

  3. Ohno, Y. et al. Electrical spin injection in a ferromagnetic semiconductor heterostructure. Nature 402, 790–792 (1999).

    Article  CAS  Google Scholar 

  4. Dietl, T., Ohno, H., Matsukura, F., Cibert, J. & Ferrand, D. Zener model description of ferromagnetism in zinc-blende magnetic semiconductors. Science 287, 1019–1022 (2000).

    Article  CAS  Google Scholar 

  5. Dietl, T., Ohno, H. & Matsukura, F. Hole-mediated ferromagnetism in tetrahedrally coordinated semiconductors. Phys. Rev. B 63, 195205 (2001).

    Article  Google Scholar 

  6. Mašek, J. et al. Microscopic analysis of the valence band and impurity band theories of (Ga,Mn)As. Phys. Rev. Lett. 105, 227202 (2010).

    Article  Google Scholar 

  7. Neumaier, D. et al. All-electrical measurement of the density of states in (Ga,Mn)As. Phys. Rev. Lett. 103, 087203 (2009).

    Article  CAS  Google Scholar 

  8. Hirakawa, K., Katsumoto, S., Hayashi, T., Hashimoto, Y. & Iye, Y. Double-exchange-like interaction in Ga1−xMnxAs investigated by infrared absorption spectroscopy. Phys. Rev. B 65, 193312 (2002).

    Article  Google Scholar 

  9. Burch, K. S. et al. Impurity band conduction in a high temperature ferromagnetic semiconductor. Phys. Rev. Lett. 97, 087208 (2006).

    Article  CAS  Google Scholar 

  10. Sapega, V. F., Moreno, M., Ramsteiner, M., Däweritz, L. & Ploog, K. H. Polarization of valence band holes in the (Ga,Mn)As diluted magnetic semiconductor. Phys. Rev. Lett. 94, 137401 (2005).

    Article  CAS  Google Scholar 

  11. Ando, K., Saito, H., Agarwal, K. C., Debnath, M. C. & Zayets, V. Origin of the anomalous magnetic circular dichroism spectral shape in ferromagnetic Ga1−xMnxAs: Impurity bands inside the band gap. Phys. Rev. Lett. 100, 067204 (2008).

    Article  CAS  Google Scholar 

  12. Rokhinson, L. P. et al. Weak localization in Ga1−xMnxAs: Evidence of impurity band transport. Phys. Rev. B 76, 161201(R) (2007).

    Article  Google Scholar 

  13. Alberi, K. et al. Formation of Mn-derived impurity band in III-Mn-V alloys by valence band anticrossing. Phys. Rev. B 78, 075201 (2008).

    Article  Google Scholar 

  14. Ohya, S., Takata, K. & Tanaka, M. Nearly non-magnetic valence band of the ferromagnetic semiconductor GaMnAs. Nature Phys. 7, 342–347 (2011).

    Article  CAS  Google Scholar 

  15. Dobrowolska, M. et al. Controlling the Curie temperature in (Ga,Mn)As through location of the Fermi level within the impurity band. Nature Mater. 11, 444–449 (2012).

    Article  CAS  Google Scholar 

  16. Sato, K. et al. First-principles theory of dilute magnetic semiconductors. Rev. Mod. Phys. 82, 1633–1690 (2010).

    Article  CAS  Google Scholar 

  17. Edmonds, K. W. et al. High-Curie-temperature Ga1−xMnxAs obtained by resistance-monitored annealing. Appl. Phys. Lett. 81, 4991–4993 (2002).

    Article  CAS  Google Scholar 

  18. Olejnı´k, K. et al. Enhanced annealing, high Curie temperature, and low-voltage gating in (Ga,Mn)As: A surface oxide control study. Phys. Rev. B 78, 054403 (2008).

    Article  Google Scholar 

  19. Okabayashi, J. et al. Angle-resolved photoemission study of Ga1−xMnxAs. Phys. Rev. B 64, 125304 (2001).

    Article  Google Scholar 

  20. Powell, C. J., Jablonski, A., Tilinin, I. S., Tanuma, S. & Penn, D. R. Surface sensitivity of Auger-electron spectroscopy and X-ray photoelectron spectroscopy. J. Electron Spectrosc. Relat. Phenom. 98, 1–15 (1999).

    Article  Google Scholar 

  21. Tanuma, S., Powell, C. J. & Penn, D. R. Calculations of electron inelastic mean free paths. IX. Data for 41 elemental solids over the 50 eV to 30 keV range. Surf. Interface Anal. 43, 689–713 (2011).

    Article  CAS  Google Scholar 

  22. Papp, C. et al. Band mapping in X-ray photoelectron spectroscopy: An experimental and theoretical study of W(110) with 1.25 keV excitation. Phys. Rev. B 84, 045433 (2011).

    Article  Google Scholar 

  23. Gray, A. X. et al. Probing bulk electronic structure with hard X-ray angle-resolved photoemission. Nature Mater. 10, 759–764 (2011).

    Article  CAS  Google Scholar 

  24. Braun, J., Minár, J., Ebert, H., Katsnelson, M. I. & Lichtenstein, A. I. Spectral function of ferromagnetic 3d metals: A self-consistent LSDA+DMFT approach combined with the one-step model of photoemission. Phys. Rev. Lett. 97, 227601 (2006).

    Article  CAS  Google Scholar 

  25. Braun, J., Minár, J., Matthes, F., Schneider, C. M. & Ebert, H. Theory of relativistic photoemission for correlated magnetic alloys: LSDA+DMFT study of the electronic structure of NixPd1−x . Phys. Rev. B 82, 024411 (2010).

    Article  Google Scholar 

  26. Shevchik, N. J. Disorder effects in angle-resolved photoelectron spectroscopy. Phys. Rev. B 16, 3428–3442 (1977).

    Article  CAS  Google Scholar 

  27. Hussain, Z., Fadley, C. S. & Kono, S. Temperature-dependent angle-resolved X-ray photoemission study of the valence bands of single-crystal tungsten: Evidence for direct transitions and phonon effects. Phys. Rev. B 22, 3750–3766 (1980).

    Article  CAS  Google Scholar 

  28. Fadley, C. S. X-ray photoelectron spectroscopy: Progress and perspectives. J. Electron Spectrosc. Relat. Phenom. 178–179, 2–32 (2010).

    Article  Google Scholar 

  29. Vincente Alvarez, M. A., Ascolani, H. & Zampieri, G. Excitation of phonons and forward focusing in X-ray photoemission from the valence band. Phys. Rev. B 54, 14703–14712 (1996).

    Article  Google Scholar 

  30. Boekelheide, Z. et al. Band gap and electronic structure of an epitaxial, semiconducting Cr0.80Al0.20 thin film. Phys. Rev. Lett. 105, 236404 (2010).

    Article  CAS  Google Scholar 

  31. Sato, K., Dederichs, P. H., Katayama-Yoshida, H. & Kudrnovsky, J. Exchange interactions in diluted magnetic semiconductors. J. Phys. Condens. Matter 16, S5491–S5497 (2004).

    Article  CAS  Google Scholar 

  32. Trzhaskovskaya, B., Nefedov, V. I. & Yarzhemsky, V. G. Photoelectron angular distribution parameters for elements Z = 55 to Z = 100 in the photoelectron energy range 100–5000 eV. Atom. Data Nucl. Data Tables 82, 257–311 (2002).

    Article  CAS  Google Scholar 

  33. Sato, K., Dederichs, P. H. & Katayama-Yoshida, H. Curie temperatures of dilute magnetic semiconductors from LDA+U electronic structure calculations. Physica B 376–377, 639–642 (2006).

    Article  Google Scholar 

  34. Dubon, O. D., Scarpulla, M. A., Farshchi, R. & Yu, K. M. Doping and defect control of ferromagnetic semiconductors formed by ion implantation and pulsed-laser melting. Physica B 376, 630–634 (2006).

    Article  Google Scholar 

  35. Scarpulla, M. A. et al. Ferromagnetic Ga1−xMnxAs produced by ion implantation and pulsed-laser melting. Appl. Phys. Lett. 82, 1251–1253 (2003).

    Article  CAS  Google Scholar 

  36. Edmonds, K. W. et al. Surface effects in Mn L3,2 X-ray absorption spectra from (Ga,Mn)As. Appl. Phys. Lett. 84, 4065–4067 (2004).

    Article  CAS  Google Scholar 

  37. Scarpulla, M. A. et al. Electrical transport and ferromagnetism in Ga1−xMnxAs synthesized by ion implantation and pulsed-laser melting. J. Appl. Phys. 103, 073913 (2008).

    Article  Google Scholar 

  38. Ueda, S. et al. Present status of the NIMS contract beamline BL15XU at SPring-8. AIP Conf. Proc. 1234, 403–406 (2010).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

This work was funded by the US Department of Energy under Contract No. DE-AC02-05CH11231, including salary and travel support for C.S.F. and A.X.G. The authors are grateful to HiSOR, Hiroshima University and JAEA/SPring-8 for the development of HXPS at BL15XU of SPring-8. The experiments at BL15XU were performed under the approval of NIMS Beamline Station (Proposal No. 2009A4906). This work was partially supported by the Nanotechnology Network Project, MEXT, Japan. Research at Stanford was supported through the Stanford Institute for Materials and Energy Science and the LCLS by the US Department of Energy, Office of Basic Energy Sciences. Financial support from German funding agencies DFG (SFB 689, EB 154/18 and EB 154/20) and the German ministry BMBF (05K10WMA) is also gratefully acknowledged (J.M., J.B. and H.E.).

Author information

Authors and Affiliations

Authors

Contributions

A.X.G. and S.U. carried out the experiments, with assistance from Y.Y. and under the supervision of K.K. and C.S.F. Data normalization and analysis were performed by A.X.G and under the supervision of C.S.F. Theoretical calculations were carried out by J.M. J.B. and H.E. (one-step theory), and by L.P. with support from C.M.S. (additional free-electron final-state theory band structure). Samples were grown by P.R.S. under the supervision on O.D.D. Additional supporting measurements were carried out by J.F. under the supervision of G.P.

Corresponding author

Correspondence to A. X. Gray.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Gray, A., Minár, J., Ueda, S. et al. Bulk electronic structure of the dilute magnetic semiconductor Ga1−xMnxAs through hard X-ray angle-resolved photoemission. Nature Mater 11, 957–962 (2012). https://doi.org/10.1038/nmat3450

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nmat3450

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