Room-temperature ferromagnetism in hydrothermally treated fullerene

Abstract

We have studied the effects of hydrothermal treatment on fullerene (C-60) by means of the magnetization and ferromagnetic resonance (FMR) measurements. Room-temperature ferromagnetism was observed in hydrothermally treated fullerene by the magnetization measurements, and a prominent FMR signal was also detected. The magnetization curves were analyzed by employing ferromagnetic and paramagnetic contributions. Thus, a spin-1/2 species was identified in the paramagnetic pristine fullerene, which may be attributed to hydrogen or C-OH bonds. In contrast, a spin-3/2 species was identified in the ferromagnetic hydrothermally treated fullerene, which may be explained by a hydrogen atom adsorbed to a carbon vacancy.