Possible Room Temperature Ferromagnetism in Hydrogenated Carbon Nanotubes

TL;DR

This study demonstrates that hydrogenation of carbon nanotubes induces ferromagnetism with a high Curie temperature near 1000 K, suggesting potential for room temperature magnetic applications.

Contribution

It is the first to show hydrogen-induced ferromagnetism in carbon nanotubes with detailed analysis of conditions and magnetic behavior.

Findings

Hydrogen incorporation leads to significant ferromagnetic moments.

Curie temperature observed near 1000 K.

Ferromagnetism depends on nanotube size and hydrogen uptake.

Abstract

We find that ferromagnetism can be induced in carbon nanotubes (CNTs) by introducing hydrogen. Multiwalled CNTs grown inside porous alumina templates contain a large density of defects resulting in significant hydrogen uptake when annealed at high temperatures. This hydrogen incorporation produces H-complex and adatom magnetism which generates a sizeable ferromagnetic moment and a Curie temperature near Tc=1000 K. We studied the conditions for the incorporation of hydrogen, the temperature-dependent magnetic behavior, and the dependence of the ferromagnetism on the size of the nanotubes.