Minimal Surfaces, Screw Dislocations and Twist Grain Boundaries

TL;DR

This paper demonstrates that large and small twist-angle grain boundaries in layered structures can be described within a unified framework, emphasizing the importance of screw-dislocation core structures in their energetic comparison.

Contribution

It reveals that the distinction between Scherk's surfaces and screw dislocation arrays is not fundamental, highlighting the role of core structures in their energetics.

Findings

Large and small twist-angle boundaries are described similarly.

Core structures critically influence energetic differences.

Unified description of grain boundary types.

Abstract

Large twist-angle grain boundaries in layered structures are often described by Scherk's first surface whereas small twist-angle grain boundaries are usually described in terms of an array of screw dislocations. We show that there is no essential distinction between these two descriptions and that, in particular, their comparative energetics depends crucially on the core structure of their screw-dislocation topological defects.