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Synthesis and thermodynamic properties of nanoalloys

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The MeANS group has been working on the fabrication and the structural characterization of bimetallic nanoparticles, namely nanoalloys, since 2004. We have developed vapor phase deposition techniques (thermal evaporation and pulsed laser deposition) that allow fabricating nanoalloys with tunable size and composition. MeANS scientists use and develop the multi-functionalities of transmission electron microscopy, particularly aberration-corrected resolution imaging, to study the growth mechanisms and the nanophase diagram of nanoalloys. Indeed, beside the composition and temperature that influence the atomic structure of bulk materials, the structure of nanoalloys is also influenced by their size, shape, interfaces with the environment and possible crystal defects. Thus, understanding the complex thermodynamic properties of nanoalloys is an indispensable prerequisite because we cannot exploit their physical and chemical properties if we don’t control their atomic-scale structure. Motivated by promising magnetic, optic or catalytic properties, the MeANS group has deeply investigated CoPt, CuAg, AuPd and AuCu nanoparticles in close collaboration with theoreticians predicting the nanophase diagram of nanoalloys with atomistic simulations

Aberration-corrected transmission electron microscopy : a multi-functional tool to study the atomic structure of nanoalloys

Projects :

Main collaborators : Hakim AMARA (LEM, CNRS-ONERA), Jérôme Creuze (ICMO, Université d’Orsay), Christine Mottet (CiNAM, Université d’Aix-Marseille), Riccardo Ferrando (Department of Chemistry and Industrial Chemistry, University of Genoa, Italy).

Main publications :

Direct Measurement of the Surface Energy of Bimetallic Nanoparticles : Evidence of Vegard’s Rulelike Dependence
A. Chmielewski, J. Nelayah, H. Amara, J. Creuze, D. Alloyeau, G. Wang, C. Ricolleau
Phys. Rev. Lett. 120, 025901

Ostwald-Driven Phase Separation in Bimetallic Nanoparticle Assemblies
G. Prévot, N. T. Nguyen, D. Alloyeau, C. Ricolleau, J. Nelayah
ACS Nano, 10 (4), 4127-4133 (2016)

New insights into the mixing of gold and copper in a nanoparticle from a structural study of Au–Cu nanoalloys synthesized via a wet chemistry method and pulsed laser deposition
Hélène Prunier, Jaysen Nelayah, Christian Ricolleau, Guillaume Wang, Sophie Nowak, Anne-Félicie Lamic-Humblot and Damien Alloyeau
Phys. Chem. Chem. Phys. (2015)

Nanoalloys : Synthesis, Structure and Properties
Damien Alloyeau, Christine Mottet, Christian Ricolleau
Book published by Springer in 2012. ISBN : 978-1-4471-4013-9

Transition from core–shell to Janus chemical configuration for bimetallic nanoparticles
C. Langlois, Z. L. Li, J. Yuan, D. Alloyeau, J. Nelayah, D. Bochicchio, R. Ferrando and C. Ricolleau
Nanoscale , 4, 3381-3388 (2012)

Following Ostwald ripening in nanoalloys by high-resolution imaging with single-atom chemical sensitivity
D. Alloyeau, T. Oikawa, J. Nelayah, G. Wang, C. Ricolleau
Applied Physics Letters. 101, 121920 (2012)

Ostwald ripening in nanoalloys : when thermodynamics drives a size-dependant particle composition
D. Alloyeau, G. Prevot, C. Ricolleau, Y. Le Bouar, C. Langlois, T. Oikawa, A. Loiseau
Phys. Rev. Letters 105, 255901 (2010)

Size and shape effects on the order-disorder phase transition in CoPt nanoparticles
D. Alloyeau, C. Ricolleau, C. Mottet, T. Oikawa, C. Langlois, Y. Le Bouar, N. Braidy, A. Loiseau
Nature Materials, 8, 940-946 (2009)