Dislocations & Colloids Dislocations: Line defects in 3D xtals. Point defects in 2D xstals (Often difficult to study in atomic systems) Colloids: small particles that are Brownian and therefore thermal (Form crystals, easy to see, slow) Schall et al., SCIENCE 305, 1944-1948 (Sep 2004) Schall et al., NATURE 440: 319- 323 (Mar 2006)
32
Embed
Dislocations & ColloidsDislocations & Colloids Dislocations: Line defects in 3D xtals. Point defects in 2D xstals ... • Plasticity, yield, and other material properties are well
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Dislocations & ColloidsDislocations: Line defects in 3D xtals. Point defects in 2D xstals
(Often difficult to study in atomic systems)
Colloids: small particles that are Brownian and therefore thermal
(Form crystals, easy to see, slow)
Schall et al., SCIENCE 305,
1944-1948 (Sep 2004)
Schall et al., NATURE 440: 319-
323 (Mar 2006)
Restricted Dislocation Mobility
in Colloidal Peanut Crystals
Itai Cohen
Sharon J. Gerbode
Stephanie H. Lee
Chekesha M. Liddell
Physics
Materials Science and Engineering
Cornell University, Ithaca NY 900nm
Degenerate Crystal*
*K.W. Wojciechowski et al., PRL1991
• Particle centers form
a sparse, aperiodic
decoration of a
Kagomé lattice
• Particle lobes tile a
triangular lattice
• Particle orientations
uniformly populate 3
lattice directions
Familiar turf: 2-D crystals of spheres
Vast existing body of knowledge on hard spheres:
• Standard structure characterization – triangular peaks
in g(r) and sixfold coordination
• Plasticity, yield, and other material properties are well
described by established theories of dislocation motion
(Taylor, Orowan, Polanyi, 1934)
• 2-D melting is extensively studied: KTHNY theory of