Ferromagnetic carbon with enhanced Curie temperature

The discovery of a ferromagnetic form of carbon (Nature 413 (2001) 716) gives a new perspective in the investigation of magnetic materials. The existence of a ferromagnetic state with the very high Curie temperature T-C approximate to 500 K for a material with only s- and p-electrons as well as the nature of its underlying interaction are of great fundamental interest. Here we report on the observation of the ferromagnetically ordered state in a material obtained by high-pressure high-temperature treatment of the fullerene C-60. It has a saturation magnetization more than four times larger than that reported previously. From our data we estimated the considerably higher value of T-C approximate to 820 K. (C) 2003 Elsevier Science B.V. All rights reserved.