Nanocrystal

Source: Wikipedia, the free encyclopedia.
This article is about crystalline nanoparticles. For other nanocrystalline materials, see
Nanocrystalline
.

A nanocrystal is a material particle having at least one dimension smaller than 100 nanometres, based on quantum dots

crystalline arrangement.[2]

The size of nanocrystals distinguishes them from larger

crystals
. For example, silicon nanocrystals can provide efficient light emission while bulk silicon does not[3] and may be used for memory components.[4]

When embedded in solids, nanocrystals may exhibit much more complex melting behaviour than conventional solids

macroscopic samples of a similar material without the complicating presence of grain boundaries and other defects.[citation needed
]

Semiconductor nanocrystals having dimensions smaller than 10 nm are also described as quantum dots.

Synthesis

The traditional method involves molecular precursors, which can include typical metal salts and a source of the anion. Most semiconducting nanomaterials feature chalcogenides (SS−, SeS−, TeS−) and pnicnides (P3−, As3−, Sb3−). Sources of these elements are the silylated derivatives such as bis(trimethylsilyl)sulfide (S(SiMe3)2 and tris(trimethylsilyl)phosphine (P(SiMe3)3).[7]

Nanoscale tertiary phosphine-stabilized Ag-S cluster prepared from molecular precursors. Color code: gray = Ag, violet = P, orange = S.[8]

Some procedures use surfactants to solubilize the growing nanocrystals.[9] In some cases, nanocrystals can exchange their elements with reagents through atomic diffusion.[9]

Applications

Filter

Nanocrystals made with zeolite are used to filter crude oil into diesel fuel at an ExxonMobil oil refinery in Louisiana at a cost less than conventional methods.[10]

Wear resistance

Nanocrystals' level of hardness

wear resistance industry[13][14]

See also

References

  1. ^ B. D. Fahlman (2007). Material Chemistry. Vol. 1. Springer: Mount Pleasant, Michigan. pp. 282–283.
  2. doi:10.1016/j.jcrysgro.2005.09.060
    .
  3. ^ L. Pavesi (2000). "Optical gain in silicon nanocrystals". Nature. 408 (6811): 440–444.
    PMID 11100719
    .
  4. ^ S. Tiwari (1996). "A silicon nanocrystal based memory". Appl. Phys. Lett. 68 (10): 1377–1379.
    doi:10.1063/1.116085
    .
  5. ^ J. Pakarinen (2009). "Partial melting mechanisms of embedded nanocrystals". Phys. Rev. B. 79 (8): 085426.
    doi:10.1103/physrevb.79.085426
    .
  6. ^ D. V. Talapin (2012). "Nanocrystal solids: A modular approach to materials design". MRS Bulletin. 37: 63–71.
    S2CID 138791528
    .
  7. PMID 22918377
    .
  8. PMID 14705083
    .
  9. ^
    S2CID 206549388
    .
  10. ^ P. Dutta and S. Gupta (eds.) (2006). Understanding of Nano Science and Technology (1 ed.). Global Vision Publishing House. p. 72.
    ISBN 81-8220-188-8. {{cite book}}: |author= has generic name (help
    )
  11. doi:10.1016/j.apsusc.2013.04.062
    .
  12. ^ "Kenneth Nordtvedt Molecular Hardness - the Genetic Atlas".
  13. doi:10.2174/1573413712666160530123834
    .
  14. doi:10.1016/j.comptc.2015.03.004
    .

External links

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