Ultrahigh Magnetic Fields Produced by Shearing Carbon Nanotubes

TL;DR

This paper demonstrates that sheared single-walled carbon nanotubes exhibit magnetic moments capable of generating ultrahigh magnetic fields, offering a low-energy, high-temperature alternative to traditional magnetic field generation methods.

Contribution

It reveals that cutting SWNTs induces significant magnetic moments at their ends, enabling ultrahigh magnetic fields without extreme conditions.

Findings

Average magnetic moment of 41.5+-9.8 μB per carbon atom at 300K.

Magnetic moments originate from dangling bonds at shearing ends.

Potential for high magnetic fields at higher temperatures with low energy use.

Abstract

In laboratories, ultrahigh magnetic fields are usually produced with very large currents through superconducting, resistive or hybrid magnets, which require extreme conditions, such as low temperature, huge cooling water or tens of megawatts of power. In this work we report that when single walled carbon nanotubes (SWNTs) are cut, there are magnetic moments at the shearing end of SWNTs. The average magnetic moment is found to be 41.5+-9.8uB per carbon atom in the end states with a width of 1 nm at temperature of 300.0K, suggesting ultrahigh magnetic fields can be produced. The dangling sigma and pi bonds of the carbon atoms at the shearing ends play important roles for this unexpectedly high magnetic moments because the oxidation temperature of cut SWNTs is found to be as low as 312 in dry air. Producing ultrahigh magnetic field with SWNTs has the advantage of working at higher working temperature and with low energy consumption, suggesting great potentials of applications.