Title: High-temperature crystallization of nanocrystals into three-dimensional superlattices

Abstract

Crystallization of colloidal nanocrystals into superlattices represents a practical bottom-up process with which to create ordered metamaterials with emergent functionalities. With precise control over the size, shape and composition of individual nanocrystals, various single-and multi-component nanocrystal superlattices have been produced, the lattice structures and chemical compositions of which can be accurately engineered. Nanocrystal superlattices are typically prepared by carefully controlling the assembly process through solvent evaporation or destabilization or through DNA-guided crystallization. Slow solvent evaporation or cooling of nanocrystal solutions (over hours or days) is the key element for successful crystallization processes. Here we report the rapid growth (seconds) of micrometre-sized, face-centred-cubic, three-dimensional nanocrystal superlattices during colloidal synthesis at high temperatures (more than 230 degrees Celsius). Using in situ small-angle X-ray scattering, we observe continuous growth of individual nanocrystals within the lattices, which results in simultaneous lattice expansion and fine nanocrystal size control due to the superlattice templates. Thermodynamic models demonstrate that balanced attractive and repulsive interparticle interactions dictated by the ligand coverage on nanocrystal surfaces and nanocrystal core size are responsible for the crystallization process. The interparticle interactions can also be controlled to form different superlattice structures, such as hexagonal close-packed lattices. In conclusion, the rational assembly of variousmore » nanocrystal systems into novel materials is thus facilitated for both fundamental research and for practical applications in the fields of magnetics, electronics and catalysis.« less

Authors:

Wu, Liheng ^[1]; Willis, Joshua J. ^[2]; McKay, Ian Salmon ^[2]; Diroll, Benjamin T. ^[3]; Qin, Jian ^[2]; Cargnello, Matteo ^[4]; Tassone, Christopher J. ^[5]

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+ Show Author Affiliations

1. SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Synchrotron Radiation Lightsource; Stanford Univ., CA (United States). Dept. of Chemical Engineering
2. Stanford Univ., CA (United States). Dept. of Chemical Engineering
3. Argonne National Lab. (ANL), Argonne, IL (United States). Center for Nanoscale Materials
4. Stanford Univ., CA (United States). Dept. of Chemical Engineering, SUNCAT Center or Interface Science and Catalysis
5. SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Synchrotron Radiation Lightsource

Publication Date:

Mon Jul 31 00:00:00 EDT 2017

Research Org.:

SLAC National Accelerator Lab., Menlo Park, CA (United States); Argonne National Lab. (ANL), Argonne, IL (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1390306

Alternate Identifier(s):

OSTI ID: 1389631

Grant/Contract Number:  

AC02-76SF00515; AC02-06CH11357

Resource Type:

Accepted Manuscript

Journal Name:

Nature (London)

Additional Journal Information:

Journal Name: Nature (London); Journal Volume: 548; Journal ID: ISSN 0028-0836

Publisher:

Nature Publishing Group

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; nanoparticles; molecular self-assembly; synthesis and processing; solid-state chemistry; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY