Probing bulk electronic structure with hard X-ray angle-resolved photoemission

Article metrics

Abstract

Traditional ultraviolet/soft X-ray angle-resolved photoemission spectroscopy (ARPES) may in some cases be too strongly influenced by surface effects to be a useful probe of bulk electronic structure. Going to hard X-ray photon energies and thus larger electron inelastic mean-free paths should provide a more accurate picture of bulk electronic structure. We present experimental data for hard X-ray ARPES (HARPES) at energies of 3.2 and 6.0 keV. The systems discussed are W, as a model transition-metal system to illustrate basic principles, and GaAs, as a technologically-relevant material to illustrate the potential broad applicability of this new technique. We have investigated the effects of photon wave vector on wave vector conservation, and assessed methods for the removal of phonon-associated smearing of features and photoelectron diffraction effects. The experimental results are compared to free-electron final-state model calculations and to more precise one-step photoemission theory including matrix element effects.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Figure 1: Hard X-ray angle-resolved photoemission (HARPES) measurements and theory for W(110) at a photon energy of 5,956 eV.
Figure 2: HARPES measurements and theory for GaAs(001) at a photon energy of 3,238 eV.
Figure 3: First-principles local density calculations of the GaAs band structure.

References

  1. 1

    Himpsel, F. J. Angle-resolved measurements of the photoemission of electrons in the study of solids. Adv. Phys. 32, 1–51 (1983).

  2. 2

    Hüfner, S. Photoelectron Spectroscopy: Principles and Applications 2nd edn (Springer, 1996).

  3. 3

    Damascelli, A., Hussain, Z. & Shen, Z-X. Angle-resolved photoemission studies of the cuprate superconductors. Rev. Mod. Phys. 75, 473–541 (2003).

  4. 4

    Christensen, N. E. & Feuerbacher, B. Volume and surface photoemission from tungsten. I. Calculation of band structure and emission spectra. Phys. Rev. B 10, 2349–2372 (1974).

  5. 5

    Feydt, J., Elbe, A., Engelhard, H. & Meister, G. Photoemission from bulk bands along the surface normal of W(110). Phys. Rev. B 58, 14007–14012 (1998).

  6. 6

    Hussain, Z., Fadley, C. S., Kono, S. & Wagner, L. F. 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).

  7. 7

    Emtsev, K. V., Speck, F., Seyller, T. & Ley, L. Interaction, growth, and ordering of epitaxial graphene on SiC{0001} surfaces: A comparative photoelectron spectroscopy study. Phys. Rev. B 77, 155303 (2008).

  8. 8

    Ando, T., Fowler, A. B. & Stern, F. Electronic properties of two-dimensional systems. Rev. Mod. Phys. 54, 437–672 (1982).

  9. 9

    Tamai, A. et al. Fermi surface and van Hove singularities in the itinerant metamagnet Sr3Ru2O7 . Phys. Rev. Lett. 101, 026407 (2008).

  10. 10

    Claesson, T. et al. Angle resolved photoemission from Nd1.85Ce0.15CuO4 using high energy photons: A Fermi surface investigation. Phys. Rev. Lett. 93, 136402 (2004).

  11. 11

    Venturini, F., Minár, J., Braun, J., Ebert, H. & Brookes, N. B. Soft x-ray angle-resolved photoemission spectroscopy on Ag(001): Band mapping, photon momentum effects, and circular dichroism. Phys. Rev. B 77, 045126 (2008).

  12. 12

    Plucinski, L. et al. Band mapping in higher-energy x-ray photoemission: Phonon effects and comparison to one-step theory. Phys. Rev. B 78, 035108 (2008).

  13. 13

    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).

  14. 14

    Fadley, C. S. X-ray photoelectron spectroscopy and diffraction in the hard X-ray regime: Fundamental considerations and future possibilities. Nucl. Instrum. Methods Phys. Res. A 547, 24–41 (2005).

  15. 15

    Kobayashi, K. High-resolution hard X-ray photoelectron spectroscopy: Application of valence band and core-level spectroscopy to materials science. Nucl. Instrum. Methods Phys. Res. A 547, 98–112 (2005).

  16. 16

    Tanuma, S., Powell, C. J. & Penn, D. R. Calculations of electron inelastic mean free paths. Surf. Interface Anal. 37, 1–14 (2005).

  17. 17

    Tanuma, S. et al. Experimental determination of electron inelastic mean free paths in 13 elemental solids in the 50 to 5000 eV energy range by elastic-peak electron spectroscopy. Surf. Interface Anal. 37, 833–845 (2005).

  18. 18

    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).

  19. 19

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

  20. 20

    Takata, Y. et al. Recoil effect of photoelectrons in the Fermi edge of simple metals. Phys. Rev. Lett. 101, 137601 (2008).

  21. 21

    Feuerbacher, B. & Christensen, N. E. Volume and surface photoemission from tungsten. II. Experiment. Phys. Rev. B 10, 2373–2390 (1974).

  22. 22

    Hussain, Z., Umbach, E., Barton, J. J., Tobin, J. G. & Shirley, D. A. Angle-resolved photoemission study of the valence bands of W(011) in the photon energy range 1100–1250 eV: Observation of strong direct transitions and phonon effects. Phys. Rev. B 25, 672–676 (1982).

  23. 23

    Ieong, M., Doris, B., Kedzierski, J., Rim, K. & Yang, M. Silicon device scaling to the sub-10-nm regime. Science 306, 2057–2060 (2004).

  24. 24

    Chau, R. et al. Benchmarking nanotechnology for high-performance and low-power logic transistor applications. IEEE Trans. Nanotech. 4, 153–158 (2005).

  25. 25

    Brammertz, G. et al. GaAs on Ge for CMOS. Thin Solid Films 517, 148–151 (2008).

  26. 26

    Ye, P. D. et al. GaAs metal–oxide–semiconductor field-effect transistor with nanometer-thin dielectric grown by atomic layer deposition. Appl. Phys. Lett. 83, 180–182 (2003).

  27. 27

    Wu, J. D., Huang, Y. S., Brammertz, G. & Tiong, K. K. Optical characterization of thin epitaxial GaAs films on Ge substrates. J. Appl. Phys. 106, 023505 (2009).

  28. 28

    Zhu, H. J. et al. Room-temperature spin injection from Fe into GaAs. Phys. Rev. Lett. 87, 016601 (2001).

  29. 29

    Dallera, C. et al. Looking 100 Å deep into spatially inhomogeneous dilute systems with hard X-ray photoemission. Appl. Phys. Lett. 85, 4532 (2004).

  30. 30

    Alvarez, M. A. V., 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).

  31. 31

    Blaha, P., Schwarz, K., Madsen, G., Kvasnicka, D. & Luitz, J. WIEN2k, an Augmented Plane Wave + Local Orbitals Program for Calculating Crystal Properties (Karlheinz Schwarz, Techn. Universit. Wien, 2001).

  32. 32

    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).

  33. 33

    Bachelet, G. B. & Christensen, N. E. Relativistic and core-relaxation effects on the energy bands of gallium arsenide and germanium. Phys. Rev. B 31, 879–887 (1985).

  34. 34

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

Download references

Acknowledgements

The authors would like to thank O. D. Dubon (UC Berkeley) for providing the GaAs sample. The authors with LBNL affiliation acknowledge support from the Director, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division, of the US Department of Energy under contract number DE-AC02-05CH11231, for salary and travel support. The measurements were performed under the approval of NIMS Beamline Station (Proposal Nos. 2008A4906, 2008B4800, 2009A4906). This work was partially supported by the Nanotechnology Network Project, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. Financial support by the Deutsche Forschungsgemeinschaft (FOR 1346, EB-154/20 and MI-1327/1) and the Bundesministerium für Bildung und Forschung (05K10WMA) is also gratefully acknowledged.

Author information

A.X.G., C.P., S.U. and B.B. 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 C.P. and A.X.G. Free-electron final-state model calculations were performed by L.P., with assistance from C.M.S. One-step model calculations were performed by J.M., J.B. and H.E. DFT calculations were performed by E.R.Y. and W.E.P.

Correspondence to A. X. Gray.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Information (PDF 870 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Gray, A., Papp, C., Ueda, S. et al. Probing bulk electronic structure with hard X-ray angle-resolved photoemission. Nature Mater 10, 759–764 (2011) doi:10.1038/nmat3089

Download citation

Further reading