碳納米泡沫,碳元素的同素異形體之一,1997年由澳大利亞國立大學的Andrei V. Rode及其合作者發現[1]。
碳納米泡沫呈蛛網狀,具有分形結構,有鐵磁性。泡沫由許多原子團簇構成,每個含有約4000個碳原子,直徑約6到9納米;其中很多原子團連在一起,形成了纖細的網。在碳納米泡沫中,有許多七邊形的結構。研究者認為,七邊形的結構造是它有很多未成對的電子的原因;泡沫也因此而具有了磁性,這是其他任何一種碳的同素異形體所沒有的特性。研究者還發現,在低於-183℃時,泡沫還具有永久磁性,但這種磁性在室溫下卻會慢慢消失。
碳納米泡沫的密度很低,與碳氣凝膠很相似,但密度是它的百分之一;它是目前世上最輕的物質之一,密度約為2–10 mg/cm3[1][2],僅是海平面上空氣密度的幾倍。
這種泡沫還是電的不良導體,可以積聚靜電而吸附在其他物質上;它的熱傳導性也很差。
它的製備方法為,在充滿氬氣的容器中放入玻璃形狀的碳,用每秒一萬次的激光脈衝轟擊,使其溫度驟升到大約1萬攝氏度並爆炸,在容器壁上即可獲得一層碳納米泡沫構成的薄膜。[來源請求]
由於納米泡沫具有的鐵磁性,將來有可能把它們的顆粒注射入人體,用來改善磁共振成像的清晰程度。它們也可能被應用到利用電子自旋或電子磁性的自旋器件中。
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.
- 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. (原始內容 (PDF)存檔於2008-07-20).
- Gamaly, E. G.; Rode, A. V. Nanostructures created by lasers (PDF). Nalwa, H. S. (編). Encyclopaedia of Nanoscience and Nanotechnology 7. Stevenson Range: American Scientific Publishers. 2004: 783–809. (原始內容 (PDF)存檔於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. (原始內容 (PDF)存檔於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. (原始內容 (PDF)存檔於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. (原始內容 (PDF)存檔於2009-09-12).
- Rode, A. V.; et al.. Magnetic properties of novel carbon allotropes. Makarova, Tatiana L.; Palacio, Fernando (編). 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. (原始內容 (PDF)存檔於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. (原始內容 (PDF)存檔於2011-02-16).