Evidence for Bulk Ripplocations in Layered Solids
Jacob Gruber, Andrew C. Lang, Justin Griggs, Mitra L. Taheri, Garritt J. Tucker & Michel W. Barsoum
Scientific Reports 6, Article number: 33451 (2016) doi: 10.1038/srep33451
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Ceramics Mechanical properties
Received: 17 February 2016 Accepted: 22 August 2016 Published online: 19 September 2016
Source/Fonte: Drexel University
Abstract
Plastically anisotropic/layered solids are ubiquitous in nature and understanding how they deform is crucial in geology, nuclear engineering, microelectronics, among other fields. Recently, a new defect termed a ripplocation–best described as an atomic scale ripple–was proposed to explain deformation in two-dimensional solids. Herein, we leverage atomistic simulations of graphite to extend the ripplocation idea to bulk layered solids, and confirm that it is essentially a buckling phenomenon. In contrast to dislocations, bulk ripplocations have no Burgers vector and no polarity. In graphite, ripplocations are attracted to other ripplocations, both within the same, and on adjacent layers, the latter resulting in kink boundaries. Furthermore, we present transmission electron microscopy evidence consistent with the existence of bulk ripplocations in Ti3SiC2. Ripplocations are a topological imperative, as they allow atomic layers to glide relative to each other without breaking the in-plane bonds. A more complete understanding of their mechanics and behavior is critically important, and could profoundly influence our current understanding of how graphite, layered silicates, the MAX phases, and many other plastically anisotropic/layered solids, deform and accommodate strain.
Acknowledgements
We would like to thank Prof. R. Doherty for his usual insightful and quite helpful comments. This work was funded by ARO (W911NF-11-1-0525). ACL and MLT gratefully acknowledge support from the Office of Naval Research under grant number N000141410058. This material is based on work partially supported through a GAANN fellowship (Ja. G.).
Author information
Affiliations
Department of Materials Science and Engineering, Drexel University, Philadelphia, PA 19104, USA.
Jacob Gruber, Andrew C. Lang, Justin Griggs, Mitra L. Taheri, Garritt J. Tucker & Michel W. Barsoum
Contributions
Ja. G. carried out the simulations, A.L. obtained and analyzed the TEM micrographs under the supervision of M.L.T. Ju. G. carried out the nanoindentation experiments, prepared the TEM samples and assisted in the TEM work. G.J.T. and M.W.B. planned and supervised the research. All authors wrote the manuscript.
Competing interests
The authors declare no competing financial interests.
Corresponding authors
Correspondence to Garritt J. Tucker or Michel W. Barsoum.
