查看完整版本: 纳米粒子可能更加具有刚性Noble metal nanoparticles unexpectedly stiff

纳米粒子可能更加具有刚性Noble metal nanoparticles unexpectedly stiff

[color=blue]【纳米科技世界快讯】根据最近ETH Zurich in Switzerland的科学家的研究报道（详见[/color][url=http://link.aps.org/abstract/PRL/v100/e045502][color=blue][i]Phys. Rev. Lett.[/i] [b]100[/b] 045502[/color][/url][color=blue]），惰性金属银河金纳米粒子的刚性比其块材料还要强。这种性能可能为这类材料在纳米结构的应用开辟一条新的途径。[/color]
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}-no-d1` "The most exciting is that gold and silver, elements well known for a long time and widely used because of properties like ductility, can still show some unexpected properties," team member Guenter Krauss told nanotechweb.org.
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The researchers found that gold and silver nanoparticles around 10–30 nm in size were significantly stiffer then their bulk counterparts. For example, gold has a bulk modulus of around 171 GPa while nanoparticles of gold can reach 290 GPa. The corresponding figures for silver are around 116 GPa for the bulk and 139 GPa for nanoparticles./k%CRf\tH }
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The team determined the stiffness of the nanoparticles by taking X-ray diffraction (XRD) spectra of the materials and measuring their lattice parameters as a function of applied pressure up to 30 GPa, which was produced using a diamond anvil cell. These experiments were carried out at the Swiss Light Source using synchrotron radiation.

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.HHA4i#S)F$~X High-resolution transmission electron microscopy and XRD also identified a disordered microstructure – "polysynthetic domain twinning" and lamellar defects – as being responsible for the increased stiffness observed. This result needs to be confirmed by further detailed structure analysis of the nanoparticles though, stresses Krauss.X~a(oa;i5cP

#e5F+F {'I:]_ "The high stiffness could be useful in materials where the chemical properties of the noble metals are needed, but where a higher stiffness is desirable too," he said. "Examples include nanocomposites with tailored properties."$z6C x;I6cs$m9l3t$O
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The scientists will now focus on other elemental nanoparticles, which are likely to display the same trend.oc},|/|^"LBW7T(V

8BGg"z._N The work was reported in [url=http://link.aps.org/abstract/PRL/v100/e045502][color=#0000ff][i]Phys. Rev. Lett.[/i] [b]100[/b] 045502[/color][/url]. G7Z}C-S;X5n

zBT%r|:x'o [[i] 本帖最后由 nano 于 2008-04-13 03:46 编辑 [/i]]

好好东西！！！
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