Tunable Magnetism in Carbon-Ion-Implanted Highly Oriented Pyrolytic Graphite

Stable, room-temperature ferromagnetism in carbon - more precisely, highly oriented pyrolytic graphite - with Curie temperature as high as 460 K is reported. The magnetization can be easily tuned by controlling the low-energy carbon ion implantation dose used to create the samples. Theory indicates that the ferromagnetic order likely results from itinerant pi-electrons from defects (see figure).