(276g) Strain Fields in Repulsive Colloidal Crystals

Crystalline defects can be approximated as linear combinations of local motifs (strains) under the framework of linear elasticity theory. This approach has been widely employed in the metallurgical community; here we show that the elastic strain field approximation is a useful tool in colloidal crystalline systems as well.

This work explores the behavior of elastic moduli and strain fields around dislocations within simulated colloidal crystals interacting through a family of repulsive potentials with varying steepness. For steeper potentials, it is found that free energies of deformation are more dominated by entropy, tension-compression asymmetry near dislocation core increases, and the strain range of linear elastic applicability shrinks. We show that pressure is a key parameter for expanding the window of linear elastic applicability for very steep potentials. Using these insights, we show under what conditions linear elasticity theory can be used as a predicative tool in exploring defect-defect interactions in colloidal crystals.