2 research outputs found
Possible Room Temperature Ferromagnetism in Hydrogenated Carbon Nanotubes
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.Comment: 15 pages with 3 figures included; Accepted by Phys. Rev.
Investigation of electrical transport in hydrogenated multiwalled carbon nanotubes
Highly disordered multiwalled carbon nanotubes of large outer diameter (~60 nm) fabricated by means of chemical vapor deposition process inside porous alumina templates exhibit ferromagnetism when annealed in a H2/Ar atmosphere. In the presence of an applied magnetic field, there is a transition from positive to negative magnetoresistance. The transition may be explained in terms of the Bright model for ordered and disordered carbon structures. Additionally, temperature dependent electrical transport experiments exhibit a zero-bias anomaly at low temperature