Abstract
Icosahedral symmetry, which is not compatible with truly long-range order, canbefoundinmany systems, such as liquids, glasses, atomic clusters, quasicrystals and virus-capsids(1-12). To obtain arrangements with a high degree of icosahedral order from tens of particles or more, interparticle attractive interactions are considered to be essential(1,3,6-12). Here, we report that entropy and spherical confinement suffice for the formation of icosahedral clusters consisting of up to 100,000 particles. Specifically, by using real-space measurements on nanometre- and micrometre-sized colloids, as well as computer simulations, we show that tens of thousands of hard spheres compressed under spherical confinement spontaneously crystallize into icosahedral clusters that are entropically favoured over the bulk face-centred cubic crystal structure(13,14). Our findings provide insights into the interplay between confinement and crystallization and into how these are connected to the formation of icosahedral structures.
| Original language | English |
|---|---|
| Pages (from-to) | 56-60 |
| Number of pages | 5 |
| Journal | Nature Materials |
| Volume | 14 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Jan 2015 |
Funding
We thank R. J. A. Moes (who is funded by the FOM programme Control over Functional Nanoparticle Solids (FNPS)) for synthesis of the semiconductor particles, A. Kuijk for the synthesis of the silica colloids, and T. H. Besseling for the two-dimensional tracking. We thank J. R. Edison, W. Vlug and R. v. Roij for critical reading of the manuscript. B.d.N. acknowledges financial support from a 'Nederlandse Organisatie voor Wetenschappelijk Onderzoek' (NWO) CW grant. M.D. and F.S. acknowledge financial support from an NWO-VICI grant. S.D. and M.D. acknowledge financial support from an NWO-CW-Echo grant.
Keywords
- HARD-SPHERES
- CRYSTAL NUCLEATION
- PHASE-BEHAVIOR
- PACKING
- NANOCRYSTALS
- SUSPENSIONS
- EVOLUTION
- SYMMETRY
- GLASSES
- LIQUIDS