Magnetic carbon nanofoams.
Carbon nanofoams (CNFs) were prepared by air cooling the pyrolysate of high purified acetylene gas. Each particle of the nanofoam was constructed by 2 to 4 mutually nested carbon balls with approximately 300 nm in diameter. Carbon sheets with negative Gaussian curvature are present in the carbon ball, especially at the fringe of the ball. Undoubted room temperature ferromagnetism with saturation magnetization of 0.11 emu/g at 300 K in CNFs can be attributed to the carbon balls themselves instead of impurities. The origin of the ferromagnetism was discussed in terms of the special nested structure in CNFs.
Li
Shandong
S
Department of Physics, Fujian Normal University, Fuzhou 350007, China.
Ji
Guangbin
G
Lü
Liya
L