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The structure and chemistry of the TiO2-rich surface of SrTiO3 (001)


Oxide surfaces are important for applications in catalysis and thin film growth. An important frontier in solid-state inorganic chemistry is the prediction of the surface structure of an oxide. Comparatively little is known about atomic arrangements at oxide surfaces at present, and there has been considerable discussion concerning the forces that control such arrangements. For instance, one model suggests that the dominant factor is a reduction of Coulomb forces1; another favours minimization of ‘dangling bonds’ by charge transfer to states below the Fermi energy2. The surface structure and properties of SrTiO3—a standard model for oxides with a perovskite structure—have been studied extensively3,4,5,6,7,8,9,10,11,12,13,14. Here we report a solution of the 2 × 1 SrTiO3 (001) surface structure obtained through a combination of high-resolution electron microscopy and theoretical direct methods. Our results indicate that surface rearrangement of TiO6-x units into edge-sharing blocks determines the SrO-deficient surface structure of SrTiO3. We suggest that this structural concept can be extended to perovskite surfaces in general.

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Figure 1: Bright-field image and off-zone-axis diffraction pattern (inset) of the (2 × 1) SrTiO3 (001) surface, taken using the UHV-H9000 Hitachi transmission electron microscope (TEM).
Figure 2: High-resolution image of the 2 × 1 SrTiO3 (001) surface.
Figure 3: Theoretical direct methods solution of the (2 × 1) structure.
Figure 4: The 2 × 1 SrTiO3 (001) surface structure.


  1. Wolf, D. Reconstruction of NaCl surfaces from a dipolar solution to the Madelung problem. Phys. Rev. Lett. 68, 3315–3318 (1992)

    ADS  CAS  Article  Google Scholar 

  2. Pashley, M. D. Electron counting model and its application to island structures on molecular-beam epitaxy grown GaAs(001) and ZnSe(001). Phys. Rev. B 40, 10481–10487 (1998)

    ADS  Article  Google Scholar 

  3. Kawasaki, M. et al. Atomic control of the SrTiO3 crystal-surface. Science 266, 1540–1542 (1994)

    ADS  CAS  Article  Google Scholar 

  4. Cord, B. & Courths, R. Electronic study of SrTiO3 surfaces by photoemission. Surf. Sci. 162, 34–38 (1985)

    ADS  CAS  Article  Google Scholar 

  5. Jiang, Q. D. & Zegenhagen, J. c(6 × 2) and c(4 × 2) reconstruction of SrTiO3 (001). Surf. Sci. 425, 343–354 (1999)

    ADS  CAS  Article  Google Scholar 

  6. Naito, M. & Sato, H. Reflection high-energy electron diffraction study on the SrTiO3 surface structure. Physica C 229, 1–11 (1994)

    ADS  CAS  Article  Google Scholar 

  7. Jiang, Q. D. & Zegenhagen, J. SrTiO3 (001)-c(6 × 2): A long-range, atomically ordered surface stable in oxygen and ambient air. Surf. Sci. 367, L42–L46 (1996)

    ADS  CAS  Article  Google Scholar 

  8. Nishimura, T., Ikeda, A., Namba, H., Morishita, T. & Kido, S. Structure change of TiO2-terminated SrTiO3 (001) surfaces by annealing in O2 atmosphere and ultra-high vacuum. Surf. Sci. 421, 273–278 (1999)

    ADS  CAS  Article  Google Scholar 

  9. Liang, Y. & Bonnell, D. A. Atomic structures of reduced SrTiO3 (001) surfaces. Surf. Sci. Lett. 285, L510–L516 (1993)

    ADS  CAS  Google Scholar 

  10. Matsumoto, T., Tanaka, H., Kawai, T. & Kawai, S. STM-imaging of a SrTiO3 (100) surface with atomic-scale resolution. Surf. Sci. 278, L153–L158 (1992)

    ADS  CAS  Article  Google Scholar 

  11. Szot, K. & Speier, W. Surfaces of reduced and oxidized SrTiO3 from atomic force microscopy. Phys. Rev. B 60, 5909–5926 (1999)

    ADS  CAS  Article  Google Scholar 

  12. Padilla, J. & Vanderbilt, D. Ab initio study of SrTiO3 . Surf. Sci. 418, 64–70 (1998)

    ADS  CAS  Article  Google Scholar 

  13. Aruta, C. Structure of superconducting [BaCuOx]2/[CaCuO2]n superlattices on SrTiO3 (001) investigated by X-ray scattering. Phys. Status Solidi A 183, 353–364 (2001)

    ADS  CAS  Article  Google Scholar 

  14. Droopard, R. et al. Development of high dielectric constant epitaxial oxides on silicon by molecular beam epitaxy. Mater. Sci. Eng. B 87, 292–296 (2001)

    Article  Google Scholar 

  15. Marks, L. D. et al. Direct methods for surfaces. Surf. Rev. Lett. 5, 1087–1106 (1998)

    ADS  CAS  Article  Google Scholar 

  16. Marks, L. D., Erdman, N. & Subramanian, A. Crystallographic direct methods for surfaces. J. Phys. Condens. Matter 13, 10677–10688 (2001)

    ADS  CAS  Article  Google Scholar 

  17. Collazo-Davila, C., Grozea, D. & Marks, L. D. Determination and refinement of the Ag/Si(111)-(3 × 1) surface structure. Phys. Rev. Lett. 80, 1678–1681 (1998)

    ADS  CAS  Article  Google Scholar 

  18. Marks, L. D., Sinkler, W. & Landree, E. A feasible set approach to the crystallographic phase problem. Acta Cryst. 55, 601–612 (1999)

    CAS  Article  Google Scholar 

  19. Xu, P. & Marks, L. D. Intensities of surface diffraction spots in plan view. Ultramicroscopy 45, 155–157 (1992)

    Article  Google Scholar 

  20. Collazo-Davila, C. et al. Design and initial performance of an ultrahigh vacuum Sample Preparation Evaluation Analysis and Reaction (SPEAR) system. J. Microsc. Soc. Am. 1, 267–279 (1995)

    CAS  Google Scholar 

  21. Marks, L. D. Wiener-filter enhancement of noisy HREM images. Ultramicroscopy 62, 43–52 (1996)

    CAS  Article  Google Scholar 

  22. Marks, L. D. & Plass, R. Atomic-structure of Si(111)-(5 × 2)-Au from high resolution electron microscopy and heavy-atom holography. Phys. Rev. Lett. 75, 2172–2175 (1995)

    ADS  CAS  Article  Google Scholar 

  23. Bengu, E. et al. Imaging the dimers in Si(111)-(7 × 7). Phys. Rev. Lett. 77, 4226–4228 (1996)

    ADS  CAS  Article  Google Scholar 

  24. Kresse, G. & Hafner, J. Ab-initio molecular dynamics for liquid metals. Phys. Rev. B 47, 558–561 (1993)

    ADS  CAS  Article  Google Scholar 

  25. Kresse, G. & Furthmuller, J. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys. Rev. B 54, 11169–11186 (1996)

    ADS  CAS  Article  Google Scholar 

  26. Vanderbilt, D. Soft self-consistent pseudopotentials in a generalized eigenvalue problem. Phys. Rev. B 41, 7892–7895 (1990)

    ADS  CAS  Article  Google Scholar 

  27. Perdew, J. P. in Electronic Structure of Solids '91 (eds Ziesche, P. & Eschrig, H.) 11 (Akademie, Berlin, 1991)

    Google Scholar 

  28. Warschkow, O., Dyke, J. M. & Ellis, D. E. A divide-and-conquer implementation of the discrete variational DFT method for large molecular and solid systems. J. Comp. Phys. 143, 70–89 (1998)

    ADS  CAS  Article  Google Scholar 

  29. Jayaram, G., Xu, P. & Marks, L. D. Atomic structure of the Si (001) 2 × 1 surface. Phys. Rev. Lett. 71, 3489–3492 (1993)

    ADS  CAS  Article  Google Scholar 

  30. Xu, P., Jayaram, G. & Marks, L. D. Cross-correlation method for intensity measurement of transmission electron-diffraction patterns. Ultramicroscopy 53, 15–18 (1994)

    Article  Google Scholar 

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HREM analysis was carried out at the Electron Microscopy Collaborative Research Center at Argonne National Laboratory. This work was supported by the EMSI program of the National Science Foundation and the US Department of Energy Office of Science at the Northwestern University Institute for Environmental Catalysis. M.A. acknowledges funding from the National Science Foundation.

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Correspondence to Laurence D. Marks.

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Erdman, N., Poeppelmeier, K., Asta, M. et al. The structure and chemistry of the TiO2-rich surface of SrTiO3 (001). Nature 419, 55–58 (2002).

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