Growth pathways of Au, AgAu and PtPd nanoparticles starting from fcc seeds El yakout El koraychy 1 , Cesare Roncaglia 1 , Diana Nelli 1 , Manuella Cerbelaud 2 , Chloé Minnai 3 and Riccardo Ferrando 4 1 Dipartimento di Fisica dell’Università di Genova, Italy, 2 Université de Limoges, France, 3 Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, Japan, 4 Dipartimento di Fisica dell’Università di Genova and CNR-IMEM, Italy The growth of pure Au nanoparticles and of AgAu and PtPd nanoalloys is studied by Molecular Dynamics (MD) simulations.For pure Au,weanalyzethe growth of multiply twinned Au nanoparticles (MTPs), decahedra and icosahedra, from a tetrahedral (Th) initial seed in the gas phase [1]. The existing experimental observations show that MTPs can form from Thviadifferent pathways,butwithoutidentifyingthekeyatomistic mechanisms responsible for these growth pathways. OurMDresults reveal thesemechanisms and give a clear explanation ofthe origin of thetwinning process.In the case of nanoalloys,it is shown thatthe out-of-equilibrium core@shell chemical ordering of AuAg and PtPd can be obtaineddepositing a pure metal on an initial intermixed seed[2].Since in these systems there is no lattice mismatch between the species, the growth leads to quite regular fcc structures resembling those obtained for the pure metals. As for chemical ordering, the purity of the outer shell depends on the mobility of the minority atoms. References 1. El Koraychy, E. Y., Roncaglia, C., Nelli, D., Cerbelaud, M., & Ferrando, R. (2022)Nanoscale horizons 2. El Koraychy, E. Y., Nelli, D., Roncaglia, C., Minnai, C., & Ferrando, R. Eur. Phys. J. Appl. Phys., 97 (2022) 28
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