碳纳米泡沫
碳纳米泡沫,碳元素的同素异形体之一,1997年由澳大利亚国立大学的Andrei V. Rode及其合作者发现[1]。
碳纳米泡沫呈蛛网状,具有分形结构,有铁磁性。泡沫由许多原子团簇构成,每个含有约4000个碳原子,直径约6到9纳米;其中很多原子团连在一起,形成了纤细的网。在碳纳米泡沫中,有许多七边形的结构。研究者认为,七边形的结构造是它有很多未成对的电子的原因;泡沫也因此而具有了磁性,这是其他任何一种碳的同素异形体所没有的特性。研究者还发现,在低于-183℃时,泡沫还具有永久磁性,但這種磁性在室溫下卻會慢慢消失。
碳纳米泡沫的密度很低,与碳气凝胶很相似,但密度是它的百分之一;它是目前世上最轻的物质之一,密度约为2–10 mg/cm3[1][2],仅是海平面上空气密度的几倍。
这种泡沫还是电的不良导体,可以积聚静电而吸附在其他物质上;它的热传导性也很差。
它的制备方法为,在充满氩气的容器中放入玻璃形状的碳,用每秒一万次的激光脉冲轰击,使其温度骤升到大约1万摄氏度并爆炸,在容器壁上即可获得一层碳纳米泡沫构成的薄膜。[來源請求]
由于纳米泡沫具有的铁磁性,将来有可能把它们的颗粒注射入人体,用来改善磁共振成像的清晰程度。它们也可能被应用到利用电子自旋或电子磁性的自旋器件中。
参考文献
- ^ 1.0 1.1 Rode, Andrei V.; et al.. Structural analysis of a carbon foam formed by high pulse-rate laser ablation. Applied Physics A: Materials Science & Processing. 1999, 69 (7): S755–S758. doi:10.1007/s003390051522.
- ^ Zani, A.; Dellasega, D.; Russo, V.; Passoni, M. Ultra-low density carbon foams produced by pulsed laser deposition. Carbon: 358–365. doi:10.1016/j.carbon.2013.01.029.
扩展阅读
此节的引用需要清理,使其符合格式。 (2009年3月1日) |
- Rode, A. V.; Gamaly, E. G.; Luther-Davies, B. Formation of cluster-assembled carbon nano-foam by high-repetition-rate laser ablation. Applied Physics A: Materials Science & Processing. 2000, 70 (2): 135–144. doi:10.1007/s003390050025.
- Rode, Andrei; Gamaly, Eugene; Luther-Davies, Barry. "Method for deposition of thin films", International Patent Application No. PCT/AU98/00739, priority date 11 September, 1997; "Method of deposition of thin films of amorphous and crystalline microstructures based on ultrafast pulsed laser deposition", US 6312760 (2001).
- Rode, A. V.; et al.. Electronic and magnetic properties of carbon nanofoam produced by high-repetition-rate laser ablation. Applied Surface Science. 2002,. 197–198: 644–649. doi:10.1016/S0169-4332(02)00433-6.
- Rode, A. V.; et al.. Unconventional magnetism in all-carbon nanofoam (PDF). Phys. Rev. B. 2004, 70 (5): 054407. doi:10.1103/PhysRevB.70.054407. (原始内容 (PDF)存档于2008-07-20).
- Gamaly, E. G.; Rode, A. V. Nanostructures created by lasers (PDF). Nalwa, H. S. (编). Encyclopaedia of Nanoscience and Nanotechnology 7. Stevenson Range: American Scientific Publishers. 2004: 783–809. (原始内容 (PDF)存档于2012-03-18).
- Rode, A. V.; et al.. Strong paramagnetism and possible ferromagnetism in pure carbon nanofoam produced by laser ablation (PDF). Journal of Magnetism and Magnetic Materials. 2005,. 290–291 (1): 298–301. doi:10.1016/j.jmmm.2004.11.213. (原始内容 (PDF)存档于2011-02-16).
- Arčon, D.; et al.. Origin of Magnetic Moments in Carbon Nanofoam (PDF). Phys. Rev. B. 2006, 74 (1): 014438. doi:10.1103/PhysRevB.74.014438. (原始内容 (PDF)存档于2009-09-12).
- Blinc, R.; et al.. 13C NMR and EPR of carbon nanofoam (PDF). Physica Status Solidi B. 2006, 243 (13): 3069–3072. doi:10.1002/pssb.200669152. (原始内容 (PDF)存档于2009-09-12).
- Rode, A. V.; et al.. Magnetic properties of novel carbon allotropes. Makarova, Tatiana L.; Palacio, Fernando (编). Carbon-based magnetism: an overview of the magnetism of metal free carbon-based compounds and materials (PDF). Amsterdam: Elsevier. 2006: 463–482. ISBN 0-444-51947-5. (原始内容 (PDF)存档于2012-03-18).
- Lau, D. W. M.; et al.. High-Temperature Formation of Carbon Onions within Nanofoam: An Experimental and Simulation Study (PDF). Phys. Rev. B. 2007, 75 (23): 233408. doi:10.1103/PhysRevB.75.233408. (原始内容 (PDF)存档于2011-02-16).