Dislocation Emission around Nanoindentations on a (001) fcc Metal Surface Studied by Scanning Tunneling Microscopy and Atomistic Simulations

Fuente, O. Rodrı́guez de la; Zimmerman, Jonathan A.; González, Miguel A.; Figuera, Juan de la; Hamilton, J. C.; Pai, Woei Wu; Rojo, J. M.

doi:10.1103/physrevlett.88.036101

Cited by 167 publications

(127 citation statements)

References 15 publications

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“…Here, the atoms are represented as circles, shaded according to the modulus of the slip vector. 26 The red atoms show the region of the lattice that have undergone a perfect dislocation, with Burgers' vector bϭ 1 2 ͗110͘. The green circles represent atoms on a stacking fault.…”

Section: Resultsmentioning

confidence: 99%

Modeling of stick-slip phenomena using molecular dynamics

2004

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Molecular dynamics simulations are performed to investigate the atomic-scale stick-slip phenomenon of a pyramidal diamond tip inserted into the Ag͑010͒ surface. The mechanisms behind the stick-slip events are investigated by considering sliding speeds between 1.0 and 5.0 ms Ϫ1 and vertical support displacements of 5 and 15 Å. The analysis of the dynamic features of the substrate shows that dislocations are extrinsically linked to the stick events, with the emission of a dislocation in the substrate region near the tip, when slip occurs after stick. For small vertical displacements, the scratch in the substrate is not continuous because the tip can jump over the surface when slipping, whereas at 15 Å, a continuous scratch is formed. The dynamic friction coefficient increases from ϳ0.13 to ϳ0.46 with increasing depth, but the static friction coefficient increases only from ϳ0.32 to ϳ0.54. At the larger depths the tip does not come to a halt during stick as it does for shallow indents. Instead the tip motion is more continuous with stick and slip manifested by periods of faster and slower motion. Although the exact points of stick and slip depend on the sliding speed, the damage to the substrate, the atomistic stick-slip mechanisms, and the friction coefficients are relatively independent of speed over the range of values considered.

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Section: Resultsmentioning

confidence: 99%

Modeling of stick-slip phenomena using molecular dynamics

2004

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“…Nanoindentation has become a valuable tool to study fundamental aspects of plasticity such as dislocation nucleation [1][2][3][4][5][6][7]. The power of this technique lies in its ability to probe ultra-small and therefore virtually defect-free sample volumes.…”

Section: Introductionmentioning

confidence: 99%

Dislocation nucleation in bcc Ta single crystals studied by nanoindentation

et al. 2007

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“…5 Indeed much of the understanding of the nanoindentation process has come about by a combination of scanning probe microscopy with classical and quantum moleculardynamics simulations. [5][6][7][8][9] The simulations have shown how elastic deformation can occur, 6 dislocations can propagate, 5,10,11 and the way in which pileup around the indentation hole 7 is formed. The deformation and defect propagation that occurs in crystals is anisotropic and when combined with a nonaxially symmetric indenter can induce a complicated overlap of mechanisms.…”

Section: Introductionmentioning

confidence: 99%