physics: magnetic carbon is lightest solid ever

Once upon a time, the only known forms of carbon were graphite and diamond. Buckyballs and nanotubes have been invented relatively recently, and now an international team of researchers has created yet another structure, which they have dubbed nanofoam. The extremely lightweight solid and its strange properties were discussed at the March meeting of the American Physical Society held in Montreal last week. Researchers at the Australian National University in Canberra blasted carbon with a high-powered, super-fast laser, creating clusters of carbon atomsthat were randomly interconnected into a weblike foam. The novel structure has the lowest density ever reported for a solid. Perhaps most unusual for a substance of pure carbon, nanofoam is strongly magnetic. The effect is present at room temperature, although it starts dissipating after a few hours. The researchers believe that nanofoam may have important applications for the emerging field of electronics called spintronics, as well as in medicine, where it could be used to enhance magnetic resonance imaging.

This news brief appeared in the Discoveries column of the Boston Globe’s Health/Science section on 3/30/2004.