Hostname: page-component-78c5997874-ndw9j Total loading time: 0 Render date: 2024-11-08T07:29:37.573Z Has data issue: false hasContentIssue false

Not All That's Gold Does Glitter

Published online by Cambridge University Press:  03 May 2012

Get access

Extract

Generally, when one looks up the properties of an element such as gold in an encyclopedia, one is immediately confronted with a list of established facts and figures. While many people are aware that most countries do not rely on a “gold reserve” anymore, it is surprising to learn that even basic physical and chemical properties of something as familiar as gold are not as fixed as one may believe. The reason for this is that tabulated values for material properties inevitably refer to macroscopic samples. It turns out that many simple properties such as those listed in the definition given here go spectacularly wrong as the size of the piece of gold is reduced. One of the most dramatic demonstrations of this was provided by Buffat and Borel, who measured the melting point of gold particles as a function of particle size using an electron microscope. They found that by the time gold crystals are just 4 nm across, the melting point drops to 700 K from its “encyclopedia value” of 1337 K. Another example is the noble character of gold metal.

Type
Research Article
Copyright
Copyright © Materials Research Society 2001

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1.For example, see The World Encyclopedia [CD-ROM Version], Webster Publishing, www.websterpublishing.com (1998).Google Scholar
2.Buffat, P.A. and Borel, J.-P., Phys. Rev. A 13 (1976) p.2287.CrossRefGoogle Scholar
3.The first theory of the quantum size effect for semiconductors is Brus, L.E.J. Chem. Phys. 79 (1983) p. 5566; for metal nanocrystals, the first description of quantum size effects is probably that by H. Fröhlich, Physica 4 (1937) p.406.Google Scholar
4.Henglein, A.J.Phys. Chem. 97 (1993) p.5457.Google Scholar
5.Kerker, M.The Scattering of Light and Other Electromagnetic Radiation (Academic Press, New York, 1969).Google Scholar
6.For an extensive and lucid review of the solid-state physics of small metal particles, see Perenboom, J.A.A.Wyder, P. and Meier, F.Phys. Rep. 78 (1981) p.173. Acomprehensive listing of metal nanocrystal optical spectra is given by J.A., Creighton and D.G., Eadon J. Chem. Soc., Faraday Trans. 87 (1991) p.3881, while the optics of small metals is treated in depth in U. Kreibig and M., Vollmer Optical Properties of Metal Clusters (Springer-Verlag, Berlin, 1996).CrossRefGoogle Scholar
7.Faraday, M.Philos. Trans. R. Soc. London 147 (1857) p.145.Google Scholar
8.Liz-Marzán, L.M., Giersig, M. and Mulvaney, P.Langmuir 12 (1996) p.4329.Google Scholar
9.Ung, T.Liz-Marzán, L.M., and Mulvaney, P.J.Phys. Chem. B 105 (2001) p.3441; Colloids Surf., A (2001) in press.Google Scholar
10.Martin, C.R.Science 266 (1994) p.196.CrossRefGoogle Scholar
11.Zande, B.M.I. van der, Böhmer, M.R., Fokkink, L.G.J. and Schönenberger, C., J.Phys. Chem. B 101 (1997) p. 852; B.M.I. van der Zande, PhD thesis, Utrecht University, 1998.Google Scholar
12.Yu, Y.-Y., Chang, S.-S., Lee, C.-L., and Wang, C.R.C.J.Phys. Chem. B 101 (1997) p.6661.Google Scholar
13.Jana, N.R.Gearheart, L. and Murphy, C.J.J.Phys. Chem. B 105 (2001) p.4065.CrossRefGoogle Scholar
14.Wilson, O.Wilson, G. and Mulvaney, P. Nano Lett. (2001) submitted for publication.Google Scholar
15.Hodak, J.H.Henglein, A. and Hartland, G.V.J.Phys. Chem. B 104 (2000) p.9954.Google Scholar
16.Sader, J.Hartland, G.V. and Mulvaney, P. J.Phys. Chem. B (2001) in press.Google Scholar
17.Link, S.Burda, C.Mohamed, M.B.Nikoobakht, B. and El-Sayed, M.A., J. Phys. Chem. B 103 (1999) p.1165.Google Scholar
18.Hartland, G.V. O Wilson, Sader, J. and Mulvaney, P. J.Phys. Chem. B (2001) submitted for publication.Google Scholar
19.Sönnichsen, C., Franzl, T.Wilk, T.Plessen, G. von, Feldmann, J., Wilson, O. and Mulvaney, P. Phys. Rev. Lett. (2001) in press.Google Scholar
20.Mulvaney, P.Langmuir 12 (1996) p.788.CrossRefGoogle Scholar
21.Oldfield, G.Ung, T. and Mulvaney, P.Adv. Mater. 12 (2000) p.1519.3.0.CO;2-W>CrossRefGoogle Scholar
22.Haynes, C.L. and Duyne, R.P. van, J. Phys. Chem. B 105 (2001) p.5599.Google Scholar
23.Schumacher, E.F.Small is Beautiful (Sphere Books, London, 1973) p.34.Google Scholar
24.Not all that tempts your wandring eyes/And heedless hearts, is lawful prize; Nor all, that glisters, gold.” Gray, Thomas (1716–1771), Source: Knowles, E. ed., Oxford Dictionary of Quotations, 5th Ed. (Oxford University Press, New York, 1999).Google Scholar