Uncommon dislocation processes at the incipient plasticity of stepped gold surfaces



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Navarro, V. and Rodríguez de la Fuente, Óscar and Mascaraque Susunaga, Arantzazu and Rojo Alaminos, Juan Manuel (2008) Uncommon dislocation processes at the incipient plasticity of stepped gold surfaces. Physical Review Letters, 100 (10). ISSN 0031-9007

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Official URL: http://dx.doi.org/10.1103/PhysRevLett.100.105504


Gold vicinal surfaces (788), with a high density of steps, along with (111) flat surfaces taken as a reference, have been nanoindented and their resulting penetration curves and related defect structure comparatively analyzed by AFM and atomistic simulations. Stepped surfaces are shown to yield at smaller loads than (111) ones in agreement with calculations of the critical resolved shear stress needed to nucleate a dislocation. In the stepped surfaces, a novel intermediate state is identified in which the penetration curves depart from a Hertzian behavior prior to the appearance of pop-ins. This state is shown to result from heterogeneous nucleation at preexisting surface steps of dislocation loops, most of which retract and vanish when the indenter load is removed.

Item Type:Article
Additional Information:

© 2008 The American Physical Society.
The authors thank J.E. Ortega for providing us the Au(788) sample. Financial support from the Spanish MEC, Project No. MAT2006-13149-C02-01 and from the CAM Projects Nos. CAM-S-0505/PPQ/0316 and GR/ MAT/0632/2004 are gratefully acknowledged. V. N. thanks MEC through No. MAT2003-08627-C02-01.

Uncontrolled Keywords:Defect nucleation, Nanoindentation, Simulation
Subjects:Sciences > Physics > Materials
ID Code:28334
Deposited On:16 Feb 2015 11:33
Last Modified:11 Mar 2022 17:51

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