Regensburg 2013 – scientific programme
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MI: Fachverband Mikrosonden
MI 9: Poster: Microanalysis and Microscopy
MI 9.7: Poster
Wednesday, March 13, 2013, 15:00–17:00, Poster B2
Detecting the Water Bridge Formation in Atomic Force Microscopy Using Dynamic Force Spectroscopy: Numerical Simulations and Experiments — •Mahfujur Rahaman1, Raul D. Rodriguez1, Lilibeth Leal1, Alexander Villabona1, Emmanuelle Lacaze2, Jacques Jupille2, and Dietrich R.T. Zahn1 — 1Semiconductor Physics, Chemnitz University of Technology, Chemnitz, Germany — 2Institut des Nano-Sciences de Paris (INSP), Paris, France
Experimental analysis of force spectroscopy is a challenging issue due to the high non-linearity of the tip-sample interaction forces. In this work, numerical simulations are used in order to support experimental results in dynamic mode force spectroscopy obtained on hydrophilic-hydrophilic and hydrophilic-hydrophobic systems. Several tip-sample interaction forces such as long-range van der Waals force, short-range adhesive and repulsive forces are taken into account for simulating amplitude and phase vs. distance curves (APD). In addition to these forces, it is found that capillarity plays an important role in the AFM dynamics. The capillary force arises from the formation of water meniscus due to the liquid condensation between tip and sample under ambient conditions. In this contribution we propose that the attractive/repulsive transition in APD curves are affected by this capillary force. Numerical simulations are performed taking into account capillarity with exact simulated solutions for a meniscus at different relative humidity and tip-sample distances. A good agreement between our numerical model and the experimental results has been observed.