Dynamics and instabilities of defects in two-dimensional crystals on curved backgrounds

@article{citeulike:2883886, abstract = {Point defects are ubiquitous in two-dimensional crystals and play a fundamental role in determining their mechanical and thermodynamical properties. When crystals are formed on a curved background, finite-length grain boundaries (scars) are generally needed to stabilize the crystal. We provide a continuum elasticity analysis of defect dynamics in curved crystals. By exploiting the fact that any point defect can be obtained as an appropriate combination of disclinations, we provide an analytical determination of the elastic spring constants of dislocations within scars and compare them with existing experimental measurements from optical microscopy. We further show that vacancies and interstitials, which are stable defects in flat crystals, are generally unstable in curved geometries. This observation explains why vacancies or interstitials are never found in equilibrium spherical crystals. We finish with some further implications for experiments and future theoretical work.}, author = {Bowick, Mark and Shin, Homin and Travesset, Alex }, citeulike-article-id = {2883886}, doi = {http://dx.doi.org/10.1103/PhysRevE.75.021404}, journal = {Physical Review E (Statistical, Nonlinear, and Soft Matter Physics)}, keywords = {2007, 2d, crystal, defect, pre}, number = {2}, posted-at = {2008-06-11 22:48:24}, priority = {2}, publisher = {APS}, title = {Dynamics and instabilities of defects in two-dimensional crystals on curved backgrounds}, url = {http://dx.doi.org/10.1103/PhysRevE.75.021404}, volume = {75}, year = {2007} }

TY - JOUR ID - citeulike:2883886 L3 - citeulike-article-id:2883886 TI - Dynamics and instabilities of defects in two-dimensional crystals on curved backgrounds JF - Physical Review E (Statistical, Nonlinear, and Soft Matter Physics) VL - 75 IS - 2 PB - APS N2 - Point defects are ubiquitous in two-dimensional crystals and play a fundamental role in determining their mechanical and thermodynamical properties. When crystals are formed on a curved background, finite-length grain boundaries (scars) are generally needed to stabilize the crystal. We provide a continuum elasticity analysis of defect dynamics in curved crystals. By exploiting the fact that any point defect can be obtained as an appropriate combination of disclinations, we provide an analytical determination of the elastic spring constants of dislocations within scars and compare them with existing experimental measurements from optical microscopy. We further show that vacancies and interstitials, which are stable defects in flat crystals, are generally unstable in curved geometries. This observation explains why vacancies or interstitials are never found in equilibrium spherical crystals. We finish with some further implications for experiments and future theoretical work. KW - 2007 KW - 2d KW - crystal KW - defect KW - pre AU - Bowick, Mark AU - Shin, Homin AU - Travesset, Alex PY - 2007/// UR - http://dx.doi.org/10.1103/PhysRevE.75.021404 ER -