“Supracrystalline Colloidal Eggs: Epitaxial Growth and Freestanding Three-Dimensional Supracrystals in Nanoscaled Colloidosomes”. Yang Z, Altantzis T, Zanaga D, Bals S, Van Tendeloo G, Pileni M-P, Journal of the American Chemical Society 138, 3493 (2016). http://doi.org/10.1021/jacs.5b13235
Abstract: The concept of template-confined chemical reactions allows the synthesis of complex molecules that would hardly be producible through conventional method. This idea was developed to produce high quality nanocrystals more than 20 years ago. However, template-mediated assembly of colloidal nanocrystals is still at an elementary level, not only because of the limited templates suitable for colloidal assemblies, but also because of the poor control over the assembly of nanocrystals within a confined space. Here, we report the design of a new system called “supracrystalline colloidal eggs” formed by controlled assembly of nanocrystals into complex colloidal supracrystals through superlattice-matched epitaxial overgrowth along the existing colloidosomes. Then, with this concept, we extend the supracrystalline growth to lattice-mismatched binary nanocrystal superlattices, in order to reach anisotropic superlattice growths, yielding freestanding binary nanocrystal supracrystals that could not be produced previously.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 13.858
Times cited: 57
DOI: 10.1021/jacs.5b13235
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“Thermal Stability of CoAu13Binary Nanoparticle Superlattices under the Electron Beam”. Altantzis T, Yang Z, Bals S, Van Tendeloo G, Pileni M-P, Chemistry of materials 28, 716 (2016). http://doi.org/10.1021/acs.chemmater.5b04898
Abstract: One primary goal of self-assembly in nanoscale regime is to implement multifunctional binary nanoparticle superlattices into practical use. In the last decade, considerable effort has been put into the fabrication of binary nanoparticle superlattices with controllable structure and stoichiometry. However, limited effort has been made in order to improve the stability of these binary nanoparticle superlattices, which is a prerequisite for their potential application. In this work, we demonstrate that the carbon deposition from specimen contamination can play an auxiliary role during the heat treatment of binary nanoparticle superlattices. With the in-situ carbon matrix formation, the thermal stability of CoAu 13 binary nanoparticle superlattices is unambiguously enhanced.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 10
DOI: 10.1021/acs.chemmater.5b04898
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“Do Binary Supracrystals Enhance the Crystal Stability?”.Yang Z, Altantzis T, Bals S, Tendeloo GV, Pileni M-P, The journal of physical chemistry: C : nanomaterials and interfaces 122, 13515 (2018). http://doi.org/10.1021/acs.jpcc.7b12373
Abstract: We study the oxygen thermal stability of two binary
systems. The larger particles are magnetic amorphous Co (7.2 nm) or
Fe3O4 (7.5 nm) nanocrystals, whereas the smaller ones (3.7 nm) are
Au nanocrystals. The nanocrystal ordering as well as the choice of the
magnetic nanoparticles very much influence the stability of the binary
system. A perfect crystalline structure is obtained with the Fe3O4/Au
binary supracrystals. For the Co/Au binary system, oxidation of Co
results in the chemical transformation from Co to CoO, where the size
of the amorphous Co nanoparticles increases from 7.2 to 9.8 nm in
diameter. During the volume expansion of the Co nanoparticles, Au
nanoparticles within the binary assemblies coalesce and are at the
origin of the instability of the binary nanoparticle supracrystals. On the
other hand, for the Fe3O4/Au binary system, the oxidation of Fe3O4 to
γ-Fe2O3 does not lead to a size change of the nanoparticles, which
maintains the stability of the binary nanoparticle supracrystals. A similar behavior is observed for an AlB2-type Co−Ag binary
system: The crystalline structure is maintained, whereas in disordered assemblies, coalescence of Ag nanocrystals is observed.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 4.536
Times cited: 5
DOI: 10.1021/acs.jpcc.7b12373
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