Applied Physics A

, Volume 117, Issue 4, pp 1689–1696 | Cite as

Dielectric sensing by charging energy modulation in a nano-granular metal



Several sensing concepts using nanostructures prepared by focused-electron-beam-induced deposition have been developed over the last years. Following work on highly miniaturized Hall sensors for magnetic sensing with soft magnetic Co, strain and force sensing based on nano-granular platinum–carbon structures (Pt(C)) was introduced. Very recently, the capability of nano-granular Pt(C) structures to detect the presence of adsorbate water layers by conductance modulations was demonstrated. For magnetic and strain sensing, the underlying physical mechanisms of the sensing effect have been analyzed in detail and are now quite well understood. This is not the case for the adsorbate layer-induced conductance modulation effect. Here, we provide a theoretical framework that allows for a semi-quantitative understanding of the observed water-sensing effect. We show how the near-interface renormalization of the Coulomb charging energy in the nano-granular metal caused by the dielectric screening of the polarizable adsorbate layer leads to a conductance modulation. The model can account for the conductance modulation observed in the water adsorbate experiments and can also be applied to understand similar effects caused by near-interface dielectric anomalies of ferroelectric thin films on top of nano-granular Pt(C). Our findings provide a pathway toward optimized nano-granular layer structures suitable for a wide range of dielectric or local potential sensing applications.


Polarizable Medium Capacitance Calculation Conductance Modulation Relative Humidity Level Transport Regime 



M. H. thanks the Deutsche Forschungsgemeinschaft for financial support through the Collaborative Research Centre SFB/TR 49.


  1. 1.
    G. Boero, I. Utke, T. Bret, N. Quack, M. Todorova, S. Mouaziz, P. Kejik, J. Brugger, R.S. Popovic, P. Hoffmann, Appl. Phys. Lett. 86, 042503 (2005)ADSCrossRefGoogle Scholar
  2. 2.
    M. Gabureac, L. Bernau, I. Utke, G. Boero, Nanotechnology 21, 115503 (2010)ADSCrossRefGoogle Scholar
  3. 3.
    C.H. Schwalb, C. Grimm, M. Baranowski, R. Sachser, F. Porrati, H. Reith, P. Das, J. Mller, F. Vlklein, A. Kaya, M. Huth, Sensors 10, 9847 (2010)CrossRefGoogle Scholar
  4. 4.
    M. Huth, F. Porrati, C.H. Schwalb, M. Winhold, R. Sachser, M. Dukic, J. Adams, G. Fantner, Beilstein J. Nanotechnol. 3, 597 (2012)CrossRefGoogle Scholar
  5. 5.
    M. Huth, J. Appl. Phys. 107, 113709 (2010)ADSCrossRefGoogle Scholar
  6. 6.
    F. Kolb, K. Schmoltner, M. Huth, A. Hohenau, J. Krenn, A. Klug, E.J.W. List, H. Plank, Nanotechnology 24, 305501 (2013)CrossRefGoogle Scholar
  7. 7.
    M. Huth, A. Rippert, R. Sachser, L. Keller, submitted to Nanotechnology (2014), arXiv:1404.7669
  8. 8.
    I.S. Beloborodov, A.V. Lopatin, V.M. Vinokur, K.B. Efetov, Rev. Mod. Phys. 79, 469 (2007)ADSCrossRefGoogle Scholar
  9. 9.
    O.G. Udalov, N.M. Chtchelkatchev, A. Glatz, I.S. Beloborodov, Phys. Rev. B 89, 054203 (2014)ADSCrossRefGoogle Scholar
  10. 10.
    F. Porrati, R. Sachser, C.H. Schwalb, A. Frangakis, M. Huth, J. Appl. Phys. 109, 063715 (2011)ADSCrossRefGoogle Scholar
  11. 11.
    H. Plank, G. Kothleitner, F. Hofer, S.G. Michelitsch, C. Gspan, A. Hohenau, J. Krenn, J. Vac. Sci. Technol. A 29, 051801 (2011)CrossRefGoogle Scholar
  12. 12.
    R. Sachser, F. Porrati, ChH Schwalb, M. Huth, Phys. Rev. Lett. 107, 206803 (2011)ADSCrossRefGoogle Scholar
  13. 13.
    C. Wasshuber, Computational Single-Electronics, 139ff (Springer, Wien, 2001)CrossRefGoogle Scholar
  14. 14.
    N. Anderson, Am. J. Phys. 38, 1483 (1970)ADSCrossRefGoogle Scholar
  15. 15.
    R.G. Barrera, O. Guzman, B. Balaguer, Am. J. Phys. 46, 1172 (1978)ADSCrossRefGoogle Scholar
  16. 16.
    J.C. Garnett, Philos. Trans. R. Soc. Lond. 203, 385 (1904); 205, 237 (1906)Google Scholar
  17. 17.
    X.C. Zeng, D.J. Bergmann, P.M. Hui, D. Stroud, Phys. Rev. B 38, 10970 (1988)ADSCrossRefGoogle Scholar
  18. 18.
    M. Uematsu, E.U. Frank, J. Phys. Chem. Ref. Data 9, 1291 (1980)ADSCrossRefGoogle Scholar
  19. 19.
    A. Gil, J. Colchero, M. Luna, J. Gomez-Herrero, A.M. Baro, Langmuir 16, 5086 (2000)CrossRefGoogle Scholar
  20. 20.
    A. Opitz, M. Scherge, S.I.-U. Ahmed, J.A. Schaefer, J. Appl. Phys. 101, 064310 (2007)ADSCrossRefGoogle Scholar
  21. 21.
    L.P. Gor’kov, G.M. Eliashberg, Sov. Phys. JETP 21, 940 (1965)ADSGoogle Scholar
  22. 22.
    M. Strässler, M.J. Rice, P. Wyder, Phys. Rev. B 6, 2575 (1972)ADSCrossRefGoogle Scholar
  23. 23.
    S.K. Saha, Phys. Rev. B 69, 125416 (2004)ADSCrossRefGoogle Scholar
  24. 24.
    A.A. Middleton, N.S. Wingreen, Phys. Rev. Lett. 71, 3198 (1993)ADSCrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.Physikalisches InstitutGoethe UniversityFrankfurt am MainGermany
  2. 2.Institute for Electron Microscopy and NanoanalysisGraz University of TechnologyGrazAustria

Personalised recommendations