Avalanches, Plasticity, and Ordering in Colloidal Crystals Under Compression
arXiv:1503.02690 · doi:10.1103/PhysRevE.93.062607
Abstract
Using numerical simulations we examine colloids with a long-range Coulomb interaction confined in a two-dimensional trough potential undergoing dynamical compression. As the depth of the confining well is increased, the colloids move via elastic distortions interspersed with intermittent bursts or avalanches of plastic motion. In these avalanches, the colloids rearrange to minimize their colloid-colloid repulsive interaction energy by adopting an average lattice constant that is isotropic despite the anisotropic nature of the compression. The avalanches take the form of shear banding events that decrease or increase the structural order of the system. At larger compressions, the avalanches are associated with a reduction of the number of rows of colloids that fit within the confining potential, and between avalanches the colloids can exhibit partially crystalline or even smectic ordering. The colloid velocity distributions during the avalanches have a non-Gaussian form with power law tails and exponents that are consistent with those found for the velocity distributions of gliding dislocations. We observe similar behavior when we subsequently decompress the system, and find a partially hysteretic response reflecting the irreversibility of the plastic events.
11 pages, 11 postscript figures
References in corpus (16)
- Power-law distributions in empirical data
- Structural defects in ion crystals by quenching the external potential: the inhomogeneous Kibble-Zurek mechanism
- Structural phase transitions in low-dimensional ion crystals
- Submicron plasticity: yield stress, dislocation avalanches, and velocity distribution
- Helical Packings and Phase Transformations of Soft Spheres in Cylinders
- Specific heat in two-dimensional melting
- Pattern formation in colloidal explosions
- Structural and dynamical properties of a quasi-one-dimensional classical binary system
- Anomalous structural and mechanical properties of solids confined in quasi one dimensional strips
- Ginzburg-Landau theory of the zig-zag transition in quasi-one-dimensional classical Wigner crystals
- Magnetic particles confined in a modulated channel: structural transitions tunable by tilting a magnetic field
- Tunable diffusion of magnetic particles in a quasi-one-dimensional channel
- Generic ordering of structural transitions in quasi-one-dimensional Wigner crystals
- Formation of defects in multirow Wigner crystals
- Structural transitions in vertically and horizontally coupled parabolic channels of Wigner crystals
- Dimensional transitions in small Yukawa clusters