Abstract
We report the production of a hierarchically nanostructured magnetic carbon foam by high-repetition-rate laser ablation of glassy carbon in Ar. The clusters contain both sp2 and sp3 bonded carbon atoms. The material contains graphite-like sheets with hyperbolic curvature, as proposed for "schwarzite". In addition to other unusual properties, the all-carbon nanofoam exhibits para- and maybe ferromagnetic behavior up to 90 K, with a narrow hysteresis curve, susceptibility of the order of 10-5 emu/g Oe, and a high saturation magnetization (up to 0.8 emu/g at 1.8 K). We postulate that localized unpaired spins occur because of topological and bonding defects associated with the sheet curvature, and that these spins are stabilized for >1 year due to the steric protection offered by the convoluted sheets.
Original language | English |
---|---|
Pages (from-to) | 298-301 |
Number of pages | 4 |
Journal | Journal of Magnetism and Magnetic Materials |
Volume | 290-291 PART 1 |
DOIs | |
Publication status | Published - Apr 2005 |