Superlattice formation in binary mixtures of hard-sphere colloids
TL;DR: Binary mixtures of suspended hard-sphere colloidal particles, radius ratio R B /R A =0.58, were observed to undergo entropically driven freezing transitions into both the AB 2 and AB 13 superlattice structures at different relative proportions of the two species.
Abstract: Binary mixtures of suspended hard-sphere colloidal particles, radius ratio ${\mathit{R}}_{\mathit{B}}$/${\mathit{R}}_{\mathit{A}}$=0.58, were observed to undergo entropically driven freezing transitions into both the ${\mathit{AB}}_{2}$ and the ${\mathit{AB}}_{13}$ superlattice structures at different relative proportions of the two species. The structures were identified by powder light crystallography and by electron microscopy of the dried solid phases. An approximate (constant volume) phase diagram containing three eutectics was determined. The results are compared with earlier work at size ratio 0.62.
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TL;DR: Nanocrystals (NCs) discussed in this Review are tiny crystals of metals, semiconductors, and magnetic material consisting of hundreds to a few thousand atoms each that are among the hottest research topics of the last decades.
Abstract: Nanocrystals (NCs) discussed in this Review are tiny crystals of metals, semiconductors, and magnetic material consisting of hundreds to a few thousand atoms each. Their size ranges from 2-3 to about 20 nm. What is special about this size regime that placed NCs among the hottest research topics of the last decades? The quantum mechanical coupling * To whom correspondence should be addressed. E-mail: dvtalapin@uchicago.edu. † The University of Chicago. ‡ Argonne National Lab. Chem. Rev. 2010, 110, 389–458 389
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TL;DR: In this article, the self-organization of CdSe nanocrystallites into three-dimensional semiconductor quantum dot superlattices (colloidal crystals) is demonstrated.
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Abstract: Chemical methods developed over the past two decades enable preparation of colloidal nanocrystals with uniform size and shape. These Brownian objects readily order into superlattices. Recently, the range of accessible inorganic cores and tunable surface chemistries dramatically increased, expanding the set of nanocrystal arrangements experimentally attainable. In this review, we discuss efforts to create next-generation materials via bottom-up organization of nanocrystals with preprogrammed functionality and self-assembly instructions. This process is often driven by both interparticle interactions and the influence of the assembly environment. The introduction provides the reader with a practical overview of nanocrystal synthesis, self-assembly, and superlattice characterization. We then summarize the theory of nanocrystal interactions and examine fundamental principles governing nanocrystal self-assembly from hard and soft particle perspectives borrowed from the comparatively established fields of micro...
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1,081 citations
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909 citations