Peierls-type metal-insulator transition in carbon nanostructures

TL;DR

This study demonstrates a Peierls-type metal-insulator transition in carbon nanostructures formed inside ZSM-5 zeolite, combining experimental observations with theoretical calculations to reveal a transition characterized by a resistance upturn and quasigap formation.

Contribution

It provides the first experimental evidence of a Peierls transition in carbon nanostructures within zeolite templates, supported by first-principles phonon mode analysis.

Findings

Resistance upturn at 30 K indicates insulating behavior

Quasigap opening at the Fermi level confirmed by differential resistance

Phonon mode softening verified through first-principles calculations

Abstract

We report the observation of Peierls-type metal-insulator transition in carbon nanostructures formed by chemical vapor deposition inside the pore network of the ZSM-5 zeolite. The Raman spectrum of this nanocarbon@ZSM-5 indicates a clear signature of the radial breathing mode (RBM) for (3,0) carbon nanotubes that can constitute the carbon network segments. Electrical transport measurements on multiple few-micron-sized nanocarbon@ZSM-5 crystals showed metallic temperature of resistance dependence down to 30 K, at which point the resistance exhibited a sharp upturn that is accompanied by the opening of a quasigap at the Fermi level as indicated by the differential resistance measurements. Further Hall measurements have yielded both the sign of the charge carrier and its density. The latter demonstrated excellent consistency with the quasigap data. We employed first-principles calculations to verify that there can indeed be softening of the phonon modes in the (3,0) carbon nanotubes.