Domain boundary formation in helical multishell gold nanowire

TL;DR

This study uses quantum mechanical molecular dynamics to explore how helical domain boundaries form in multishell gold nanowires, revealing defect-driven transformations and energetic considerations.

Contribution

It introduces a theoretical analysis of domain boundary formation in gold nanowires, highlighting defect mechanisms and energy factors involved.

Findings

Non-helical nanowires transform into helical structures with atom pair defects.

Defect formation involves atom pairs moving from inner shells to boundaries.

Energy analysis explains the competition between surface reconstruction and defect creation.

Abstract

Helical multishell gold nanowire is studied theoretically for the formation mechanism of helical domain boundary. Nanowires with the wire length of more than 10 nm are relaxed by quantum mechanical molecular dynamics simulation with tight-binding form Hamiltonian. In results, non-helical nanowires are transformed into helical ones with the formation of atom pair defects at domain boundary, where the defective atom pair is moved from an inner shell. Analysis of local electronic structure shows a competitive feature of the energy gain of reconstruction on wire surface and the energy loss of the defect formation. A simple energy scaling theory gives a general discussion of domain boundary formation.