Dislocations

In a perfect solid the material will exhibit brittle properties; however, in most solids there are a variety of defects present such as vacancies, interstitials, grain boundaries, twin boundaries, and dislocations. The motion of these defects is what leads to plastic response of materials. Plasticity is one of the most outstanding problems in materials science, with key questions including how to describe the onset of yield in materials, and the pattern formation of defects under shear. We have been modelling dislcation motion in materials under DC and AC driving, and have found evidence for critical phenomena near the onset of yield and how their connection to particular types of patterns. The above figure shows the strain fields generated by gliding dislocations under shear. Another problem we have been studying is the motion of dislocations in solid He, where unusual shear response has been found which could be related to a supersolid phase or some form of exotic motion of dislocations.

Papers:

1. Dynamic phases, pinning, and pattern formation for driven dislocation assemblies
   C. Zhou, C. Reichhardt, C.J. Olson Reichhardt, and I.J. Beyerlein
   Scientific Reports 5, 800 (2015).
   Online version

2. Random organization in periodically driven gliding dislocations
   C. Zhou, C.J. Olson Reichhardt, C. Reichhardt, and I. Beyerlein
   Phys. Lett. A 378, 22 (2014).
   Online version

3. Comment on "Giant Plasticity of a Quantum Crystal"
   C. Zhou, C. Reichhardt, M.J. Graf, J.-J Su, A.V. Balatsky and I.J. Beyerlein
   Phys. Rev. Lett 111, 119601 (2013).
   Online version

4. Plastic response of dislocation glide in solid helium under dc strain rate loading
   C. Zhou, J.J. Su, M.J. Graf, C. Reichhardt, A.V. Balatsky, and I.J. Beyerlein Phys. Rev B 88, 025413 (2013).
   Online version

5. Dislocation induced anomalous softening of solid helium
   C. Zhou, Jung-Jung Su, M.J. Graf, C. Reichhardt, A.V. Balatsky, and I.J. Beyerlein
   Philosophical Magazine Letters 92, 608 (2012).
   Online version

Collaborators

Matthias Graf (DOE)

Irene Beyerlein (LANL)

Jung-Jung Su (NCTU)

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Last Modified: 5/1/15