Influence of noncontact dissipation in the tapping mode: Attempt to extract quantitative information on the surface properties with the local force probe method

Abstract

In the Tapping mode, a variation of the oscillation amplitude and phase as a function of the tip sample distance is the necessary measurement to access quantitatively to the properties of the surface. In the present work, we give a systematic comparison between experimental data recorded on two surfaces, phase and amplitude, and theoretical curves. With an interaction between the tip and the surface taking into account an attractive and a repulsive term, the analytical approach is unable to properly describe the relationship between the phase variation and the oscillation amplitude variation. When an additional dissipation term is involved, due to the attractive interaction between the tip and the surface, the model gives a good agreement with the recorded data. Particularly, the trends in the phase variations related to the noncontact situations have been found to be amenable to an analysis based upon a simple viscoelastic behavior of the surface. ͓͔

Probing viscosity of a polymer melt at the nanometre scale with an oscillating nanotip

“…g is a function that depends on the tip shape (see Eqs. (5,6,9,10)) and on the expression of the viscous coefficient. Writing δS I diss /δϕ + δS V diss /δϕ = 0 gives the sin(ϕ) equation from which the phase variation is derived [19,17].…”

“…A detailed discussion of the use of the variational principle is given in reference [17]. In general, several ingredients have to be included in the action, i) the attractive interaction without any contact, ii) the influence of the adhesion when the tip touches intermittently the surface [8], iii) the instantaneous elastic response [17] and iv) even the non-contact dissipation which might have a sizeable influence onto the phase variation [10]. Here, we only focus on the contribution of the viscous force when the tip touches intermittently the surface.…”

“…Therefore suitable assumptions must be done in order to keep analytical solutions and to properly weight the relative importance of the different contributions to the observed oscillation behavior. Fortunately, the data available such as approach-retract curves are accurate enough to discriminate between these different contributions [4,8,10].…”

“…Any attempt to model oscillation behavior when the tip touches the sample faces several difficulties: i) the first one is the fact that a non-linear behavior often takes place, ii) secondly, it should require to properly consider the contact between the tip and the surface during a part of the oscillation period. When a contact occurs, adhesion [8], elasticity and dissipation and even non-contact dissipation [10] must be considered making models of the a e-mail: jpaime@cribx1.u-bordeaux.fr interaction truly cumbersome. Therefore suitable assumptions must be done in order to keep analytical solutions and to properly weight the relative importance of the different contributions to the observed oscillation behavior.…”

Phase imaging and the lever-sample tilt angle in dynamic atomic force microscopy

“…[6][7][8][9] Work by Burnham et al describes a full solution, including Maugis mechanics, of dynamic AFM. 6 García and San Paulo have emphasized that there are two stable regimes of dynamic AFM, one involving purely attractive forces and one that also involves repulsive forces.…”