Contrast inversion in dynamic force microscopy on silicon(111) 7×7 and gold(111) 23×

Molitor, S.; Güthner, Peter; Berghaus, Thomas M.

doi:10.1016/s0169-4332(98)00540-6

Cited by 19 publications

(14 citation statements)

References 8 publications

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“…While atomic motion plays a role in the dissipation mechanism, this motion is bistable and returns to its original position during each retraction cycle. This is consistent with the observed stability of images, so that even in the presence of significant dissipation, atomic resolution imaging is possible [4,14,15]. Atomic resolution dissipation imaging therefore results from the atom-by-atom variation of the short range interaction and thus of the energy losses as the tip is scanned across the surface.…”

supporting

confidence: 79%

Energy Dissipation in Atomic Force Microscopy and Atomic Loss Processes

et al. 2001

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Atomic scale dissipation is of great interest in nanomechanics and atomic manipulation. We present dissipation measurements with a linearized, ultra-small amplitude atomic force microscope which is capable of measuring dissipation at chosen, fixed separations. We show that the dynamic dissipation in the noncontact regime is of the order of a few 10-100 meV per cycle. This dissipation is likely due to the motion of a bistable atomic defect in the tip-surface region. In the contact regime we observe dc hysteresis associated with nanoscale plasticity. We find the hysteretic energy loss to be 1 order of magnitude higher for a silicon surface than for copper.

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supporting

confidence: 79%

Energy Dissipation in Atomic Force Microscopy and Atomic Loss Processes

et al. 2001

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“…On the other hand, the poorly understood dissipation measurements using FM-AFM have mainly been the source of questions 7 and controversies. 8,9 Dissipation contrast mechanisms in FM-AFM have been extensively studied from both experimental [10][11][12][13][14][15][16][17] and theoretical [18][19][20][21][22][23][24][25][26][27][28] perspectives. Although most postulated dissipation mechanisms have been experimentally verified, the variability in the data often exceeds theoretical predictions by orders of magnitude.…”

Section: Introductionmentioning

confidence: 99%

Decoupling conservative and dissipative forces in frequency modulation atomic force microscopy

et al. 2011

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Experiments and theoretical calculations of conservative forces measured by frequency modulation atomic force microscopy (FM-AFM) in vacuum are generally in reasonable agreement. This contrasts with dissipative forces, where experiment and theory often disagree by several orders of magnitude. These discrepancies have repeatedly been attributed to instrumental artifacts, the cause of which remains elusive. We demonstrate that the frequency response of the piezoacoustic cantilever excitation system, traditionally assumed flat, can actually lead to surprisingly large apparent damping by the coupling of the frequency shift to the drive-amplitude signal, typically referred to as the "dissipation" signal. Our theory predicts large quantitative and qualitative variability observed in dissipation spectroscopy experiments, contrast inversion at step edges and in atomic-scale dissipation imaging, as well as changes in the power-law relationship between the drive signal and bias voltage in dissipation spectroscopy. The magnitude of apparent damping can escalate by more than an order of magnitude at cryogenic temperatures. We present a simple nondestructive method for correcting this source of apparent damping, which will allow dissipation measurements to be reliably and quantitatively compared to theoretical models.

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“…1999), which relies on a number of assumptions such as the harmonic motion of the lever, a conservative interaction potential and general reversibility of the interaction. However, imaging with the large-amplitude AFM consistently involves a site-dependent damping (Molitor et al . 1999;Gotsmann et al .…”

Section: Introductionmentioning

confidence: 99%

Direct measurement of interatomic force gradients using an ultra-low-amplitude atomic force microscope

Hoffmann

Oral

Grimble

et al. 2001

Proc. R. Soc. Lond. A

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Interatomic force gradients between a W tip and a 7 × 7 reconstructed Si(111) surface were measured using an off-resonance, ultra-low-amplitude atomic force microscope (AFM) technique. The amplitudes used were less than 1 Å (peak-to-peak), which allowed direct measurement of the interaction force gradients as a function of separation. The force gradient curves are shown to consist of an attractive van der Waals part and short-range attractive and repulsive interactions. The van der Waals background can be subtracted, leaving a short-range interaction with an energy parameter of 1.9-3.4 eV and an interaction length-scale of 0.54-1.26 Å, characteristic of a single atomic bond. This correlates well with our observation of single-atom resolved force gradient images. In general, the interaction is reversible up to the zero intercept of the force gradient (inflection point of the energy). Beyond this point hysteresis tends to be observed and the onset of inelastic deformation can be clearly discerned. An analysis of the atomic scale contact gives reasonable values for the interfacial energy, yield strength, and the energy per atom needed to initiate plastic deformation

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Contrast inversion in dynamic force microscopy on silicon(111) 7×7 and gold(111) 23×

Cited by 19 publications

References 8 publications

Energy Dissipation in Atomic Force Microscopy and Atomic Loss Processes

Energy Dissipation in Atomic Force Microscopy and Atomic Loss Processes

Decoupling conservative and dissipative forces in frequency modulation atomic force microscopy

Direct measurement of interatomic force gradients using an ultra-low-amplitude atomic force microscope

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