Aggregated diamond nanorods

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Aggregated diamond nanorod ( English aggregated diamond nanorods , ADNR ) are a particularly dense form of carbon . ADNR scratches samples from natural diamond , which means it is harder and could enable tools with less wear .

Properties and manufacture

Aggregated diamond nanorods are among the hardest known materials with a static compression modulus K of up to 491  GPa (approx. 11% more than diamond with 442 GPa). Its X-ray absorption coefficient is 0.2 to 0.4% higher than that of ordinary diamond. The reason for this lies in the reduced bond distance between the carbon atoms in the outer layers of the ADNR. The first investigations on the material took place around 1990 without it being recognized as ADNR.

The material is more resistant to the conversion of the diamond structure into a graphite-like structure ( graphitization ) than natural diamond. This and the greater hardness also result in possible future areas of application for this material in the field of cutting tools and polishing and grinding media.

The systematic production was carried out for the first time by researchers from the Bavarian Geo-Institute (BGI) at the University of Bayreuth . The properties of the material were described together with researchers from the ESRF in Grenoble and the Technical University of Applied Sciences Wildau in August 2005. They succeeded in producing ADNR in high pressure presses with a diamond die cell at pressures of 24 GPa and temperatures of up to 2500 Kelvin. The starting material for this is a allotropes powder of C 60 - fullerenes . There is a second method of making ADNR. Diamond anvil cells are also used at pressures of up to 37 GPa without additional heating. In 2005 the production of larger quantities was successful. The typical ADNRs have a diameter of 5 to 20 nm and a length greater than 1 μm.

The materials have not yet been used economically because the quantities required for technical implementation in a research institute could not be generated. In parallel, other configurations have now been found that are in a comparable strength range such as. B. Nanopoly diamonds, which were developed by Tetsuo Irifune at Ehime University in 2012 and which are already being used in cutting tools.

literature

  • VD Blank, SG Buga, NR Serebryanaya, VN Denisov, GA Dubitsky, AN Ivlev, BN Mavrin, M. Yu. Popov: Ultrahard and superhard carbon phases produced from C60 by heating at high pressure: structural and Raman studies . In: Physics Letters A . tape 205 , no. 2-3 , August 11, 1995, pp. 208-216 , doi : 10.1016 / 0375-9601 (95) 00564-J .
  • VD Blank, SG Buga, NR Serebryanaya, GA Dubitsky, SN Sulyanov, M. Yu. Popov, VN Denisov, AN Ivlev, BN Mavrin: Phase transformations in solid C60 at high-pressure-high-temperature treatment and the structure of 3D polymerized fullerites . In: Physics Letters A . tape 220 , no. 1-3 , August 2, 1996, pp. 149-157 , doi : 10.1016 / 0375-9601 (96) 00483-5 .
  • Natalia Dubrovinskaia , Sergey Dub, Leonid Dubrovinsky: Superior Wear Resistance of Aggregated Diamond Nanorods . In: Nano Letters . tape 6 , no. 4 , March 1, 2006, p. 824-826 , doi : 10.1021 / nl0602084 .
  • Natalia Dubrovinskaia, Leonid Dubrovinsky, Wilson Crichton, Falko Langenhorst, Asta Richter: Aggregated diamond nanorods, the densest and least compressible form of carbon . In: Applied Physics Letters . tape 87 , no. 8 , 2005, p. 083106 , doi : 10.1063 / 1.2034101 .
  • ME Kozlov, M. Hirabayashi, K. Nozaki, M. Tokumoto, H. Ihara: Superhard form of carbon obtained from C60 at moderate pressure . In: Synthetic Metals . tape 70 , no. 1-3 , February 15, 1995, pp. 1411-1412 , doi : 10.1016 / 0379-6779 (94) 02900-J .
  • H. Szwarc, VA Davydov, SA Plotianskaya, LS Kashevarova, V. Agafonov, R. Céolin: Chemical modifications of C60 under the influence of pressure and temperature: from cubic C60 to diamond . In: Synthetic Metals . tape 77 , no. 1-3 , January 1996, pp. 265-272 , doi : 10.1016 / 0379-6779 (96) 80100-7 .

Web links

Individual evidence

  1. ↑ a b V. Blank et al .: Is C60 fullerite harder than diamond? In: Physics Letters A . tape 188 , no. 3 , 1994, p. 281-286 , doi : 10.1016 / 0375-9601 (94) 90451-0 .
  2. ↑ Natalia Dubrovinskaia, Leonid Dubrovinsky, Wilson Crichton, Falko Langenhorst, Asta Richter: Aggregated diamond nanorods, the densest and least compressible form of carbon . In: Applied Physics Letters . tape 87 , no. 8 , 2005, p. 083106 , doi : 10.1063 / 1.2034101 .
  3. ↑ Aggregated Diamond nanorods, the densest and Least Compressible form of carbon. European Synchrotron Radiation Facility, accessed October 10, 2014 .
  4. ↑ Maria Bongarz: Hart at the border. , May 21, 2013. In: Bild der Wissenschaft. No. 4, 2013, p. 106.