Effects of scars on crystalline shell stability under external pressure

TL;DR

This study investigates how defect structures, specifically scars, affect the stability of spherical crystalline shells under external pressure, revealing that scars can either weaken or strengthen shells depending on their symmetry.

Contribution

It introduces a comparative analysis of shells with minimal defects versus those with extended scars, highlighting the impact of defect arrangements on stability under pressure.

Findings

Scars that break icosahedral symmetry lower critical collapse pressure.

Scars preserving symmetry increase shell stability.

Shell shape depends on Föppl-von Kármán number.

Abstract

We study how the stability of spherical crystalline shells under external pressure is influenced by the defect structure. In particular, we compare stability for shells with a minimal set of topologically-required defects to shells with extended defect arrays (grain boundary "scars" with non-vanishing net disclination charge). We perform Monte Carlo simulations to compare how shells with and without scars deform quasi-statically under external hydrostatic pressure. We find that the critical pressure at which shells collapse is lowered for scarred configurations that break icosahedral symmetry and raised for scars that preserve icosahedral symmetry. The particular shapes which arise from breaking of an initial icosahedrally-symmetric shell depend on the F\"oppl-von K\'arm\'an number.