Issue Eur. Phys. J. AP Volume 15, Number 2, August 2001 Page(s) 141 - 147 Section Instrumentation,,Measurement,,Metrology DOI 10.1051/epjap:2001175

DOI: 10.1051/epjap:2001175

Eur. Phys. J. AP 15, 141-147 (2001)

A virtual non contact-atomic force microscope (NC-AFM): Simulation and comparison with analytical models

G. Couturier, J.P. Aimé, J. Salardenne and R. Boisgard

Centre de Physique Moléculaire Optique et Hertzienne (CPMOH), Université de Bordeaux I, 351 cours de la Libération, 33405 Talence Cedex 05, France

jpaime@frbdx11.cribx1.u-bordeaux.fr

(Received: 20 February 2001 / Revised and Accepted: 9 April 2001)

Abstract
A virtual NC-AFM machine has been built using the Matlab language. The virtual NC-AFM is identical to a real hybrid machine built with Digital Instruments and Omicron blocks. The role of every subset is described in detail, and special attention is paid to the parameters of the Automatic Gain Control (AGC) which controls the amplitude of the oscillations. The virtual machine is a powerful tool, that allows to solve, without any approximation, non linear coupled differential equations describing the physics of the tip-surface interaction. The machine is then used to study the frequency shift and damping signal in the approach-retract mode. Two types of situations are analyzed: the first one corresponds to the case where no dissipative force is introduced in the tip-surface interaction, the second one deals with dissipative forces. These last ones are here introduced by assuming a mechanical deformation of the surface under the tip. Interesting results are then obtained, in particular the fact that unstability may occur under some particular conditions. Most of the results obtained by simulation are then compared with those of analytical models already published in the literature.

PACS
68.37.Ps - Atomic force microscopy (AFM).


© EDP Sciences 2001

What is OpenURL?