Predicting the Characteristics of Defect Transitions on Curved Surfaces

TL;DR

This paper develops analytical criteria to predict defect transition behaviors on curved surfaces, considering shape effects, activation energies, and symmetry breaking, providing insights into structural transitions in cellular materials.

Contribution

It introduces general analytical criteria for defect transition characteristics on curved surfaces, accounting for activation energies and symmetry breaking, advancing understanding of defect energetics.

Findings

Universal activation energy scale identified

Transition order can be predicted from surface shape criteria

Shape symmetry influences defect transition behavior

Abstract

The energetically optimal position of lattice defects on intrinsically curved surfaces is a complex function of shape parameters. For open surfaces, a simple condition predicts the critical size for which a central disclination yields lower energy than a boundary disclination. In practice, this transition is modified by activation energies or more favorable intermediate defect positions. Here it is shown that these transition characteristics (continuous or discontinuous, first or second order) can also be inferred from analytical, general criteria evaluated from the surface shape. A universal scale of activation energy is found, and the criterion is generalized to predict transition order as symmetries such as that of the shape are broken. The results give practical insight into structural transitions to disorder in many cellular materials of technological and biological importance.