Kelvin probe force microscopy of alkali chloride thin films on Au(111)

Loppacher, Christian; Zerweck, Ulrich; Eng, Lukas M.

doi:10.1088/0957-4484/15/2/003

Cited by 71 publications

(61 citation statements)

References 25 publications

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“…For instance, NaCl, KCl, and KBr can be deposited in the form of ͑100͒-terminated layers on a number of metals as Cu, [6][7][8][9][10][11][12] Ag, [12][13][14][15][16][17][18] and Au. 19,20 These thin epitaxial films exhibit the chemical surface properties of the respective bulk insulators, but avoid charging effects, since the electrons can tunnel into the conducting underlying substrate. [21][22][23][24][25][26] Evidently, the spectroscopy of large organic molecules on insulator surfaces is highly interesting and complementary to that on metal surfaces.…”

Section: Introductionmentioning

confidence: 99%

Stable and metastable phases of PTCDA on epitaxial NaCl films on Ag(100)

et al. 2010

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Section: Introductionmentioning

confidence: 99%

Stable and metastable phases of PTCDA on epitaxial NaCl films on Ag(100)

et al. 2010

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“…[4][5][6] Its popularity in nanoscience is currently strongly increasing, finding application in a broad variety of material systems such as semiconductors, [7][8][9] insulators, [10][11][12] and organic molecules. [13][14][15] Recently, potential variations on the atomic scale have also been observed experimentally [16][17][18] as well as theoretically.…”

Section: Introductionmentioning

confidence: 99%

Toward quantitative Kelvin probe force microscopy of nanoscale potential distributions

et al. 2012

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Kelvin probe force spectroscopy (KPFS) and finite-element method (FEM) simulations were employed to investigate the averaging effect of the work function signals of nanoscale potential distributions in Kelvin probe force microscopy (KPFM). A KPFS routine is presented that enables meaningful experimental results even for electronically inhomogeneous KPFM tips. By use of this routine a strong distance dependence of the averaging effect is revealed. A combination of KPFS experiments and FEM simulations is applied to quantify the averaging effect, which simplifies comparison among different experiments and to theory. No influence of surface topography on the averaging effect was observed.

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“…In a few experiments, even molecular 10 or atomic [11][12][13] contrast has been reported. The extension of the technique to insulating surfaces was performed more recently, as demonstrated by the results reported on thin ionic films on metals 14,15 or on the contribution of bulk defects to the surface charge state of ionic crystals. 16,17 In this work, atomic corrugation of the CPD signal is reported on the ͑001͒ surface of a bulk ionic crystal of KBr.…”

Section: Introductionmentioning

confidence: 99%

Analytical approach to the local contact potential difference on (001) ionic surfaces: Implications for Kelvin probe force microscopy

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Nony²,

Loppacher³

et al. 2008

Phys. Rev. B

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104

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An analytical model of the electrostatic force between the tip of a noncontact atomic force microscope ͑nc-AFM͒ and the ͑001͒ surface of an ionic crystal is reported. The model is able to account for the atomic contrast of the local contact potential difference ͑CPD͒ observed, while nc-AFM-based Kelvin probe force microscopy ͑KPFM͒ experiments. With the goal in mind to put in evidence this short-range electrostatic force, the Madelung potential arising at the surface of the ionic crystal is primarily derived. The expression of the force, which is deduced, can be split into two major contributions: the first stands for the coupling between the microscopic structure of the tip apex and the capacitor formed between the tip, the ionic crystal, and the counterelectrode and the second term depicts the influence of the Madelung surface potential on the mesoscopic part of the tip, independent of its microscopic structure. The former has the lateral periodicity of the Madelung surface potential, whereas the latter only acts as a static component, which shifts the total force. These short-range electrostatic forces are in the range of 10 pN. Beyond the dielectric properties of the crystal, a major effect, which is responsible for the atomic contrast of the KPFM signal, is the ionic polarization of the sample due to the influence of the tip/counterelectrode capacitor. When explicitly considering the crystal polarization, an analytical expression of the bias voltage to be applied on the tip to compensate for the local CPD, i.e., to cancel the short-range electrostatic force, is derived. The compensated CPD has the lateral periodicity of the Madelung surface potential. However, the strong dependence on the tip geometry, the applied modulation voltage, and the tip-sample distance, which can even lead to an overestimation of the real surface potential, makes quantitative KPFM measurements of the local CPD extremely difficult.

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Kelvin probe force microscopy of alkali chloride thin films on Au(111)

Cited by 71 publications

References 25 publications

Stable and metastable phases of PTCDA on epitaxial NaCl films on Ag(100)

Stable and metastable phases of PTCDA on epitaxial NaCl films on Ag(100)

Toward quantitative Kelvin probe force microscopy of nanoscale potential distributions

Analytical approach to the local contact potential difference on (001) ionic surfaces: Implications for Kelvin probe force microscopy

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