Electronic and Magnetic Properties of Small Fullerene Carbon Nanobuds: A DFT Study

TL;DR

This study uses density functional theory to analyze how attaching various small fullerenes to carbon nanotubes affects their electronic and magnetic properties, revealing potential for tunable nanostructures.

Contribution

It provides a detailed DFT analysis of the electronic and magnetic properties of fullerene-based nanobuds with different fullerenes and nanotube types, highlighting their stability and property tuning.

Findings

Bond cycloaddition is the most energetically favorable attachment method.

Attaching C20 and C40 increases HOMO-LUMO gaps.

Magnetic moments vary with fullerene type and bonding nature.

Abstract

The electronic and magnetic properties of carbon nanobuds have been investigated using density functional theory. The carbon nanobuds are formed by attaching smaller fullerenes (C20, C28, C36 and C40) of variable size with (5,5) ACNT and (5,0) ZCNT. Fullerenes interact strongly with CNT surface having binding energies within the range -0.93eV to -4.06eV. The C-C bond lengths near the attachment region increase from the original C-C bond lengths. The relative stabilities of the nanobuds are closely related to C-C bond lengths and bond angles in cycloaddition reaction. Nanobuds formed by bond cycloaddition are energetically most favorable amongst all cycloadditions. The electronic and magnetic properties of nanobuds depend strongly on electronic properties of its building blocks. The attachment of C20 and C40 on CNTs open up the HOMO-LUMO gaps of nanobuds whereas C28 and C36 results in addition of impurity states near the Fermi level. The total magnetic moment of nanobuds vary from 0.28{\mu}B to 4.00{\mu}B which depend on the nature of bonding between fullerene and CNTs. The results outline the potential of nanobuds as hybrid carbon nanostructures and how their properties can be tuned with the size and type of fullerene attached.