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 p–d exchange and double exchange, thus providing a more unifying picture of this controversial material.
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Ohno, H. et al. (Ga,Mn)As: A new diluted magnetic semiconductor based on GaAs. Appl. Phys. Lett. 69, 363–365 (1996).
Ohno, H. Making nonmagnetic semiconductors ferromagnetic. Science 281, 951–956 (1998).
Ohno, Y. et al. Electrical spin injection in a ferromagnetic semiconductor heterostructure. Nature 402, 790–792 (1999).
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).
Dietl, T., Ohno, H. & Matsukura, F. Hole-mediated ferromagnetism in tetrahedrally coordinated semiconductors. Phys. Rev. B 63, 195205 (2001).
Mašek, J. et al. Microscopic analysis of the valence band and impurity band theories of (Ga,Mn)As. Phys. Rev. Lett. 105, 227202 (2010).
Neumaier, D. et al. All-electrical measurement of the density of states in (Ga,Mn)As. Phys. Rev. Lett. 103, 087203 (2009).
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).
Burch, K. S. et al. Impurity band conduction in a high temperature ferromagnetic semiconductor. Phys. Rev. Lett. 97, 087208 (2006).
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).
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).
Rokhinson, L. P. et al. Weak localization in Ga1−xMnxAs: Evidence of impurity band transport. Phys. Rev. B 76, 161201(R) (2007).
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).
Ohya, S., Takata, K. & Tanaka, M. Nearly non-magnetic valence band of the ferromagnetic semiconductor GaMnAs. Nature Phys. 7, 342–347 (2011).
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).
Sato, K. et al. First-principles theory of dilute magnetic semiconductors. Rev. Mod. Phys. 82, 1633–1690 (2010).
Edmonds, K. W. et al. High-Curie-temperature Ga1−xMnxAs obtained by resistance-monitored annealing. Appl. Phys. Lett. 81, 4991–4993 (2002).
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).
Okabayashi, J. et al. Angle-resolved photoemission study of Ga1−xMnxAs. Phys. Rev. B 64, 125304 (2001).
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).
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).
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).
Gray, A. X. et al. Probing bulk electronic structure with hard X-ray angle-resolved photoemission. Nature Mater. 10, 759–764 (2011).
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).
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).
Shevchik, N. J. Disorder effects in angle-resolved photoelectron spectroscopy. Phys. Rev. B 16, 3428–3442 (1977).
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).
Fadley, C. S. X-ray photoelectron spectroscopy: Progress and perspectives. J. Electron Spectrosc. Relat. Phenom. 178–179, 2–32 (2010).
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).
Boekelheide, Z. et al. Band gap and electronic structure of an epitaxial, semiconducting Cr0.80Al0.20 thin film. Phys. Rev. Lett. 105, 236404 (2010).
Sato, K., Dederichs, P. H., Katayama-Yoshida, H. & Kudrnovsky, J. Exchange interactions in diluted magnetic semiconductors. J. Phys. Condens. Matter 16, S5491–S5497 (2004).
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).
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).
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).
Scarpulla, M. A. et al. Ferromagnetic Ga1−xMnxAs produced by ion implantation and pulsed-laser melting. Appl. Phys. Lett. 82, 1251–1253 (2003).
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).
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).
Ueda, S. et al. Present status of the NIMS contract beamline BL15XU at SPring-8. AIP Conf. Proc. 1234, 403–406 (2010).
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.).
The authors declare no competing financial interests.
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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) doi:10.1038/nmat3450
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