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arXiv · 1504.06193

Size dependent phase diagrams of Nickel-Carbon nanoparticles

Yann Magnin·Alexandre Zappelli·Hakim Amara·François Ducastelle·Christophe Bichara
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Abstract

The carbon rich phase diagrams of nickel-carbon nanoparticles, relevant to catalysis and catalytic chemical vapor deposition synthesis of carbon nanotubes, are calculated for system sizes up to about 3 nanometers (807 Ni atoms). A tight binding model for interatomic interactions drives the Grand Canonical Monte Carlo simulations used to locate solid, core/shell and liquid stability domains, as a function of size, temperature and carbon chemical potential or concentration. Melting is favored by carbon incorporation from the nanoparticle surface, resulting in a strong relative lowering of the eutectic temperature and a phase diagram topology different from the bulk one. This should be taken into account in our understanding of the nanotube growth mechanisms.

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Yann Magnin, Alexandre Zappelli, Hakim Amara, François Ducastelle, Christophe Bichara. 2015-06-10. Size dependent phase diagrams of Nickel-Carbon nanoparticles. https://arxiv.org/abs/1504.06193

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