Single-Atom Scale Structural Selectivity in Te Nanowires Encapsulated inside Ultra-Narrow, Single-Walled Carbon Nanotubes

TL;DR

This study investigates tellurium nanowires encapsulated in ultra-narrow carbon nanotubes, revealing their structural diversity, electronic transitions, and stability influenced by nanoconfinement, with implications for future nanodevice applications.

Contribution

It provides a comprehensive analysis combining advanced imaging and ab initio predictions of Te nanowires in ultra-narrow nanotubes, highlighting confinement effects on structure and electronic properties.

Findings

Te ENs exhibit various structures depending on nanotube diameter.

A Peierls distortion and metal-insulator transition are observed.

Nanoconfinement enhances stability of the nanowires.

Abstract

Extreme nanowires (ENs) represent the ultimate class of crystals: They are the smallest possible periodic materials. With atom-wide motifs repeated in one dimension (1D), they offer a privileged perspective into the Physics and Chemistry of low-dimensional systems. Single-walled carbon nanotubes (SWCNTs) provide ideal environments for the creation of such materials. Here we present a comprehensive study of Te ENs encapsulated inside ultra- narrow SWCNTs with diameters between 0.7 nm and 1.1 nm. We combine state-of-the-art imaging techniques and 1D-adapted ab initio structure prediction to treat both confinement and periodicity effects. The studied Te ENs adopt a variety of structures, exhibiting a true 1D realisation of a Peierls structural distortion and transition from metallic to insulating behaviour as a function of encapsulating diameter. We analyse the mechanical stability of the encapsulated ENs and show that nanoconfinement is not only a useful means to produce ENs, but may actually be necessary, in some cases, to prevent them from disintegrating. The ability to control functional properties of these ENs with confinement has numerous applications in future device technologies, and we anticipate that our study will set the basic paradigm to be adopted in the characterisation and understanding of such systems.

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Full text

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