Entropy-driven crystal formation on highly strained substrates

Handle URI:
http://hdl.handle.net/10754/598202
Title:
Entropy-driven crystal formation on highly strained substrates
Authors:
Savage, John R.; Hopp, Stefan F.; Ganapathy, Rajesh; Gerbode, Sharon J.; Heuer, Andreas; Cohen, Itai
Abstract:
In heteroepitaxy, lattice mismatch between the deposited material and the underlying surface strongly affects nucleation and growth processes. The effect of mismatch is well studied in atoms with growth kinetics typically dominated by bond formation with interaction lengths on the order of one lattice spacing. In contrast, less is understood about how mismatch affects crystallization of larger particles, such as globular proteins and nanoparticles, where interparticle interaction energies are often comparable to thermal fluctuations and are short ranged, extending only a fraction of the particle size. Here, using colloidal experiments and simulations, we find particles with short-range attractive interactions form crystals on isotropically strained lattices with spacings significantly larger than the interaction length scale. By measuring the free-energy cost of dimer formation on monolayers of increasing uniaxial strain, we show the underlying mismatched substrate mediates an entropy-driven attractive interaction extending well beyond the interaction length scale. Remarkably, because this interaction arises from thermal fluctuations, lowering temperature causes such substrate-mediated attractive crystals to dissolve. Such counterintuitive results underscore the crucial role of entropy in heteroepitaxy in this technologically important regime. Ultimately, this entropic component of lattice mismatched crystal growth could be used to develop unique methods for heterogeneous nucleation and growth of single crystals for applications ranging from protein crystallization to controlling the assembly of nanoparticles into ordered, functional superstructures. In particular, the construction of substrates with spatially modulated strain profiles would exploit this effect to direct self-assembly, whereby nucleation sites and resulting crystal morphology can be controlled directly through modifications of the substrate.
Citation:
Savage JR, Hopp SF, Ganapathy R, Gerbode SJ, Heuer A, et al. (2013) Entropy-driven crystal formation on highly strained substrates. Proc Natl Acad Sci USA 110: 9301–9304. Available: http://dx.doi.org/10.1073/pnas.1221529110.
Publisher:
Proceedings of the National Academy of Sciences
Journal:
Proceedings of the National Academy of Sciences
KAUST Grant Number:
KUS-C1-018-02
Issue Date:
20-May-2013
DOI:
10.1073/pnas.1221529110
PubMed ID:
23690613
PubMed Central ID:
PMC3677474
Type:
Article
ISSN:
0027-8424; 1091-6490
Sponsors:
The authors thank James Sethna for comments. This work is supported in part by Award KUS-C1-018-02 from King Abdullah University of Science and Technology, by a National Science Foundation Division of Materials Research Career award, and by the National Nanotechnology Infrastructure Network. S.F.H. and A.H. are grateful for the support by Transregio 61 and Sonderforschungsbereich 858 (DFG).
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Full metadata record

DC FieldValue Language
dc.contributor.authorSavage, John R.en
dc.contributor.authorHopp, Stefan F.en
dc.contributor.authorGanapathy, Rajeshen
dc.contributor.authorGerbode, Sharon J.en
dc.contributor.authorHeuer, Andreasen
dc.contributor.authorCohen, Itaien
dc.date.accessioned2016-02-25T13:14:37Zen
dc.date.available2016-02-25T13:14:37Zen
dc.date.issued2013-05-20en
dc.identifier.citationSavage JR, Hopp SF, Ganapathy R, Gerbode SJ, Heuer A, et al. (2013) Entropy-driven crystal formation on highly strained substrates. Proc Natl Acad Sci USA 110: 9301–9304. Available: http://dx.doi.org/10.1073/pnas.1221529110.en
dc.identifier.issn0027-8424en
dc.identifier.issn1091-6490en
dc.identifier.pmid23690613en
dc.identifier.doi10.1073/pnas.1221529110en
dc.identifier.urihttp://hdl.handle.net/10754/598202en
dc.description.abstractIn heteroepitaxy, lattice mismatch between the deposited material and the underlying surface strongly affects nucleation and growth processes. The effect of mismatch is well studied in atoms with growth kinetics typically dominated by bond formation with interaction lengths on the order of one lattice spacing. In contrast, less is understood about how mismatch affects crystallization of larger particles, such as globular proteins and nanoparticles, where interparticle interaction energies are often comparable to thermal fluctuations and are short ranged, extending only a fraction of the particle size. Here, using colloidal experiments and simulations, we find particles with short-range attractive interactions form crystals on isotropically strained lattices with spacings significantly larger than the interaction length scale. By measuring the free-energy cost of dimer formation on monolayers of increasing uniaxial strain, we show the underlying mismatched substrate mediates an entropy-driven attractive interaction extending well beyond the interaction length scale. Remarkably, because this interaction arises from thermal fluctuations, lowering temperature causes such substrate-mediated attractive crystals to dissolve. Such counterintuitive results underscore the crucial role of entropy in heteroepitaxy in this technologically important regime. Ultimately, this entropic component of lattice mismatched crystal growth could be used to develop unique methods for heterogeneous nucleation and growth of single crystals for applications ranging from protein crystallization to controlling the assembly of nanoparticles into ordered, functional superstructures. In particular, the construction of substrates with spatially modulated strain profiles would exploit this effect to direct self-assembly, whereby nucleation sites and resulting crystal morphology can be controlled directly through modifications of the substrate.en
dc.description.sponsorshipThe authors thank James Sethna for comments. This work is supported in part by Award KUS-C1-018-02 from King Abdullah University of Science and Technology, by a National Science Foundation Division of Materials Research Career award, and by the National Nanotechnology Infrastructure Network. S.F.H. and A.H. are grateful for the support by Transregio 61 and Sonderforschungsbereich 858 (DFG).en
dc.publisherProceedings of the National Academy of Sciencesen
dc.subjectcolloidsen
dc.subjectthermodynamicsen
dc.subjectTunable Depletion Interactionen
dc.subject.meshCrystallizationen
dc.subject.meshEntropyen
dc.titleEntropy-driven crystal formation on highly strained substratesen
dc.typeArticleen
dc.identifier.journalProceedings of the National Academy of Sciencesen
dc.identifier.pmcidPMC3677474en
dc.contributor.institutionDepartment of Physics, Cornell University, Ithaca, NY 14853, USA.en
kaust.grant.numberKUS-C1-018-02en

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