Aggregated diamond nanorod

Source: Wikipedia, the free encyclopedia.
"hyperdiamond" redirects here. For 4-polytope, see 24-cell.
Natural nanodiamond aggregates from the Popigai impact structure, Siberia, Russia.[1]
Internal structure of the Popigai nanodiamonds.[1]
Internal structure of synthetic nanodiamonds.[1]

Aggregated diamond nanorods, or ADNRs, are a

nanocrystalline form of diamond
, also known as nanodiamond or hyperdiamond.

Discovery

Nanodiamond or hyperdiamond was produced by compression of

isothermal bulk modulus of 491 gigapascals (GPa), while a conventional diamond has a modulus of 442–446 GPa; these results were inferred from X-ray diffraction data, which also indicated that ADNRs are 0.3% denser than regular diamond.[3] The same group later described ADNRs as "having a hardness and Young's modulus comparable to that of natural diamond, but with 'superior wear resistance'".[4]

Hardness

A

Mohs scale of mineral hardness
.

Synthesis

ADNRs (hyperdiamonds/nanodiamonds) are produced by compressing fullerite powder—a solid form of allotropic carbon fullerene—by either of two somewhat similar methods. One uses a diamond anvil cell and applied pressure ~37 GPa without heating the cell.[6] In another method, fullerite is compressed to lower pressures (2–20 GPa) and then heated to a temperature in the range of 300 to 2,500 K (27 to 2,227 °C).[7][8][9][10] Extreme hardness of what now appears likely to have been nanodiamonds was reported by researchers in the 1990s.[5][6] The material is a series of interconnected diamond nanorods, with diameters of between 5 and 20 nanometres and lengths of around 1 micrometre each.[citation needed]

Nanodiamond aggregates ca. 1 mm in size also form in nature, from graphite upon meteoritic impact, such as that of the Popigai impact structure in Siberia, Russia.[1]

See also

  • Adamant – Mythological hardest substance
  • Carbon nanotube – Allotropes of carbon with a cylindrical nanostructure
  • Diamond – Form of carbon
  • Fullerite
     – Allotrope of carbon
  • Lonsdaleite – Hexagonal lattice allotrope of carbon
  • Mohs scale of mineral hardness
     – Qualitative scale characterizing scratch resistance
  • Rhenium diboride – chemical compound
  • Superhard material – Material with Vickers hardness exceeding 40 gigapascals

References

  1. ^
    PMID 26424384
    .
  2. S2CID 52856300
    .
  3. doi:10.1063/1.2034101
    .
  4. PMID 16608291
    .
  5. ^
    doi:10.1016/S0925-9635(97)00232-X. Archived from the original
    (PDF) on 2011-07-21.
  6. ^
    doi:10.1016/0375-9601(94)90451-0
    .
  7. doi:10.1016/0379-6779(94)02900-J
    .
  8. doi:10.1016/0375-9601(95)00564-J
    .
  9. doi:10.1016/0379-6779(96)80100-7
    .
  10. doi:10.1016/0375-9601(96)00483-5
    .

External links

Wikimedia Commons has media related to Nanodiamonds.
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