Nano Research

, Volume 8, Issue 7, pp 2223–2230 | Cite as

Chemically modified STM tips for atomic-resolution imaging of ultrathin NaCl films

  • Zhe Li
  • Koen Schouteden
  • Violeta Iancu
  • Ewald Janssens
  • Peter Lievens
  • Chris Van Haesendonck
  • Jorge I. Cerdá
Research Article

Abstract

Cl-functionalized scanning tunneling microscopy (STM) tips are fabricated by modifying a tungsten STM tip in situ on islands of ultrathin NaCl(100) films on Au(111) surfaces. The functionalized tips are used to achieve clear atomicresolution imaging of NaCl(100) islands. In comparison with bare metal tips, the chemically modified tips yield drastically enhanced spatial resolution as well as contrast reversal in STM topographs, implying that Na atoms, rather than Cl atoms, are imaged as protrusions. STM simulations based on a Green’s function formalism reveal that the experimentally observed contrast reversal in the STM topographs is due to the highly localized character of the Cl-pz states at the tip apex. An additional remarkable characteristic of the modified tips is that in dI/dV maps, a Na atom appears as a ring with a diameter that depends crucially on the tip-sample distance.

Keywords

scanning tunneling microscopy (STM) ultrathin insulating films functionalized STM-tip STM simulation 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Supplementary material

12274_2015_733_MOESM1_ESM.pdf (4.1 mb)
Supplementary material, approximately 4148 KB.

References

  1. [1]
    Gross, L.; Moll, N.; Mohn, F.; Curioni, A.; Meyer, G.; Hanke, F.; Persson, M. High-resolution molecular orbital imaging using a p-wave STM tip. Phys. Rev. Lett. 2011, 107, 086101.CrossRefGoogle Scholar
  2. [2]
    Martínez, J. I.; Abad, E.; González, C.; Flores, F.; Ortega, J. Improvement of scanning tunneling microscopy resolution with H-sensitized tips. Phys. Rev. Lett. 2012, 108, 246102.CrossRefGoogle Scholar
  3. [3]
    Krasnikov, S. A.; Lübben, O.; Murphy, B. E.; Bozhko, S. I.; Chaika, A. N.; Sergeeva, N. N.; Bulfin, B.; Shvets, I. V. Writing with atoms: Oxygen adatoms on the MoO2/Mo(110) surface. Nano Res. 2013, 6, 929–937.CrossRefGoogle Scholar
  4. [4]
    Lingley, Z.; Mahalingam, K.; Lu, S. Y.; Brown, G. J.; Madhukar, A. Nanocrystal-semiconductor interface: Atomicresolution cross-sectional transmission electron microscope study of lead sulfide nanocrystal quantum dots on crystalline silicon. Nano Res. 2014, 7, 219–227.CrossRefGoogle Scholar
  5. [5]
    Gross, L.; Mohn, F.; Moll, N.; Liljeroth, P.; Meyer, G. The chemical structure of a molecule resolved by atomic force microscopy. Science 2009, 325, 1110–1114.CrossRefGoogle Scholar
  6. [6]
    Zhao, R. Q.; Zhang, Y. F.; Gao, T.; Gao, Y. B.; Liu, N.; Fu, L.; Liu, Z. F. Scanning tunneling microscope observations of non-AB stacking of graphene on Ni films. Nano Res. 2011, 4, 712–721.CrossRefGoogle Scholar
  7. [7]
    Li, Z.; Chen, H. Y. T.; Schouteden, K.; Lauwaet, K.; Giordano, L.; Trioni, M. I.; Janssens, E.; Iancu, V.; Van Haesendonck, C.; Lievens, P. et al. Self-doping of ultrathin insulating films by transition metal atoms. Phys. Rev. Lett. 2014, 112, 026102.CrossRefGoogle Scholar
  8. [8]
    Repp, J.; Meyer, G.; Stojkovic, S. M.; Gourdon, A.; Joachim, C. Molecules on insulating films: Scanning-tunneling microscopy imaging of individual molecular orbitals. Phys. Rev. Lett. 2005, 94, 026803.CrossRefGoogle Scholar
  9. [9]
    Repp, J.; Meyer, G.; Paavilainen, S.; Olsson, F. E.; Persson, M. Imaging bond formation between a gold atom and pentacene on an insulating surface. Science 2006, 312, 1196–1199.CrossRefGoogle Scholar
  10. [10]
    Lin, X.; Nilius, N.; Freund, H. J.; Walter, M.; Frondelius, P.; Honkala, K.; Häkkinen, H. Quantum well states in twodimensional gold clusters on MgO thin films. Phys. Rev. Lett. 2009, 102, 206801.CrossRefGoogle Scholar
  11. [11]
    Repp, J.; Meyer, G.; Olsson, F. E.; Persson, M. Controlling the charge state of individual gold adatoms. Science 2004, 305, 493–495.CrossRefGoogle Scholar
  12. [12]
    Olsson, F. E.; Paavilainen, S.; Persson, M.; Repp, J.; Meyer, G. Multiple charge states of Ag atoms on ultrathin NaCl films. Phys. Rev. Lett. 2007, 98, 176803.CrossRefGoogle Scholar
  13. [13]
    Loth, S.; Lutz, C. P.; Heinrich, A. J. Spin-polarized spin excitation spectroscopy. New J. Phys. 2010, 12, 125021.CrossRefGoogle Scholar
  14. [14]
    Novaes, F. D.; Lorente, N.; Gauyacq, J. P. Quenching of magnetic excitations in single adsorbates at surfaces: Mn on CuN/Cu(100). Phys. Rev. B 2010, 82, 155401.CrossRefGoogle Scholar
  15. [15]
    Loth, S.; Baumann, S.; Lutz, C. P.; Eigler, D. M.; Heinrich, A. J. Bistability in atomic-scale antiferromagnets. Science 2012, 335, 196–199.CrossRefGoogle Scholar
  16. [16]
    Hebenstreit, W.; Redinger, J.; Horozova, Z.; Schmid, M.; Podloucky, R.; Varga, P. Atomic resolution by STM on ultra-thin films of alkali halides: Experiment and local density calculations. Surf. Sci. 1999, 424, 321–328.CrossRefGoogle Scholar
  17. [17]
    Repp, J.; Fölsch, S.; Meyer, G.; Rieder, K. H. Ionic films on vicinal metal surfaces: Enhanced binding due to charge modulation. Phys. Rev. Lett. 2001, 86, 252–255.CrossRefGoogle Scholar
  18. [18]
    Repp, J.; Meyer, G.; Rieder, K. H. Snell’s law for surface electrons: Refraction of an electron gas imaged in real space. Phys. Rev. Lett. 2004, 92, 036803.CrossRefGoogle Scholar
  19. [19]
    Repp, J.; Meyer, G.; Paavilainen, S.; Olsson, F. E.; Persson, M. Scanning tunneling spectroscopy of Cl vacancies in NaCl films: Strong electron-phonon coupling in double-barrier tunneling junctions. Phys. Rev. Lett. 2005, 95, 225503.CrossRefGoogle Scholar
  20. [20]
    Lauwaet, K.; Schouteden, K.; Janssens, E.; Van Haesendonck, C.; Lievens, P. Dependence of the NaCl/Au(111) interface state on the thickness of the NaCl layer. J. Phys.: Condens. Matter. 2012, 24, 475507.Google Scholar
  21. [21]
    Olsson, F. E.; Persson, M.; Repp, J.; Meyer, G. Scanning tunneling microscopy and spectroscopy of NaCl overlayers on the stepped Cu(311) surface: Experimental and theoretical study. Phys. Rev. B 2005, 71, 075419.CrossRefGoogle Scholar
  22. [22]
    Lauwaet, K.; Schouteden, K.; Janssens, E.; Van Haesendonck, C.; Lievens, P.; Trioni, M. I.; Giordano, L.; Pacchioni, G. Resolving all atoms of an alkali halide via nanomodulation of the thin NaCl film surface using the Au(111) reconstruction. Phys. Rev. B 2012, 85, 245440.CrossRefGoogle Scholar
  23. [23]
    Schouteden, K.; Lauwaet, K.; Janssens, E.; Barcaro, G.; Fortunelli, A.; Van Haesendonck, C.; Lievens, P. Probing the atomic structure of metallic nanoclusters with the tip of a scanning tunneling microscope. Nanoscale 2014, 6, 2170–2176.CrossRefGoogle Scholar
  24. [24]
    Cheng, Z. H.; Du, S. X.; Guo, W.; Gao, L.; Deng, Z. T.; Jiang, N.; Guo, H. M.; Tang, H.; Gao, H. J. Direct imaging of molecular orbitals of metal phthalocyanines on metal surfaces with an O2-functionalized tip of a scanning tunneling microscope. Nano Res. 2011, 4, 523–530.CrossRefGoogle Scholar
  25. [25]
    Horcas, I.; Fernandez, R.; Gomez-Rodriguez, J. M.; Colchero, J.; Gomez-Herrero, J.; Baro, A. M. WSXM: A software for scanning probe microscopy and a tool for nanotechnology. Rev. Sci. Instrum. 2007, 78, 013705.CrossRefGoogle Scholar
  26. [26]
    Hla, S. W. Scanning tunneling microscopy single atom/ molecule manipulation and its application to nanoscience and technology. J. Vac. Sci. Technol. B 2005, 23, 1351–1360.CrossRefGoogle Scholar
  27. [27]
    Hagelaar, J. H. A.; Flipse, C. F. J.; Cerdá, J. I. Modeling realistic tip structures: Scanning tunneling microscopy of NO adsorption on Rh(111). Phys. Rev. B 2008, 78, 161405.CrossRefGoogle Scholar
  28. [28]
    Cerdá, J.; Van Hove, M. A.; Sautet, P.; Salmeron, M. Efficient method for the simulation of STM images. I. Generalized Green-function formalism. Phys. Rev. B 1997, 56, 15885–15899.CrossRefGoogle Scholar
  29. [29]
    Janta-Polczynski, B. A.; Cerda, J. I.; Ethier-Majcher, G.; Piyakis, K.; Rochefort, A. Parallel scanning tunneling microscopy imaging of low dimensional nanostructures. J. Appl. Phys. 2008, 104, 023702.CrossRefGoogle Scholar
  30. [30]
    Cerdá, J.; Soria, F. Accurate and transferable extended Hückeltype tight-binding parameters. Phys. Rev. B 2000, 61, 7965–7971.CrossRefGoogle Scholar
  31. [31]
    Cerdá, J.; Yoon, A.; Van Hove, M. A.; Sautet, P.; Salmeron, M.; Somorjai, G. A. Efficient method for the simulation of STM images. II. Application to clean Rh(111) and Rh(111)+c(4×2)-2S. Phys. Rev. B 1997, 56, 15900–15918.CrossRefGoogle Scholar
  32. [32]
    Chen, W.; Madhavan, V.; Jamneala, T.; Crommie, M. F. Scanning tunneling microscopy observation of an electronic superlattice at the surface of clean gold. Phys. Rev. Lett. 1998, 80, 1469–1472.CrossRefGoogle Scholar
  33. [33]
    Kichin, G.; Weiss, C.; Wagner, C.; Tautz, F. S.; Temirov, R. Single molecule and single atom sensors for atomic resolution imaging of chemically complex surfaces. J. Am. Chem. Soc. 2011, 133, 16847–16851.CrossRefGoogle Scholar
  34. [34]
    Krenner, W.; Kuhne, D.; Klappenberger, F.; Barth, J. V. Assessment of scanning tunneling spectroscopy modes inspecting electron confinement in surface-confined supramolecular networks. Sci. Rep. 2013, 3, 1454.CrossRefGoogle Scholar
  35. [35]
    Schouteden, K.; Li, Z.; Iancu, V.; Muzychenko, D. A.; Janssens, E.; Lievens, P.; Van Haesendonck, C. Engineering the band structure of nanoparticles by an incommensurate cover layer. J. Phys. Chem. C 2014, 118, 18271–18277.CrossRefGoogle Scholar

Copyright information

© Tsinghua University Press and Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  • Zhe Li
    • 1
  • Koen Schouteden
    • 1
  • Violeta Iancu
    • 1
  • Ewald Janssens
    • 1
  • Peter Lievens
    • 1
  • Chris Van Haesendonck
    • 1
  • Jorge I. Cerdá
    • 2
  1. 1.Solid-State Physics and Magnetism SectionKU LeuvenLeuvenBelgium
  2. 2.Instituto de Ciencia de MaterialesICMM-CSICMadridSpain

Personalised recommendations