arXiv subjects

D. Schebarchov

Publications and source records attributed to D. Schebarchov.

4 recordsLinked to original sources

arXiv2006

Thermal instability of decahedral structures in platinum nanoparticles

We conduct molecular dynamics simulations of 887 and 1389-atom decahedral platinum nanoparticles using an embedded atom potential. By constructing microcanonical caloric curves, we identify structural transitions from decahedral to fcc in the particles prior to melting. The transitions take place during phase coexistence and appear to occur via melting of the decahedral structure and subsequent recrystallisation into the fcc structure.

cond-mat.mtrl-sci↗

arXiv2006

Superheating and solid-liquid phase coexistence in nanoparticles with non-melting surfaces

We present a phenomenological model of melting in nanoparticles with facets that are only partially wet by their liquid phase. We show that in this model, as the solid nanoparticle seeks to avoid coexistence with the liquid, the microcanonical melting temperature can exceed the bulk melting point, and that the onset of coexistence is a first-order transition. We show that these results are consistent with molecular dynamics simulations of aluminum nanoparticles which remain solid above the bulk melting temperature.

cond-mat.mtrl-sci↗

arXiv2006

Solid-liquid phase coexistence and structural transitions in palladium clusters

We use molecular dynamics with an embedded atom potential to study the behavior of palladium nanoclusters near the melting point in the microcanonical ensemble. We see transitions from both fcc and decahedral ground state structures to icosahedral structures prior to melting over a range of cluster sizes. In all cases this transition occurs during solid-liquid phase coexistence and the mechanism for the transition appears to be fluctuations in the molten fraction of the cluster and subsequent recrystallization into the icosahedral structure.

cond-mat.other↗

arXiv2005

Transition from Icosahedral to Decahedral Structure in a Coexisting Solid-Liquid Nickel Cluster

We have used molecular dynamics simulations to construct a microcanonical caloric curve for a 1415-atom Ni icosahedron. Prior to melting the Ni cluster exhibits static solid-liquid phase coexistence. Initially a partial icosahedral structure coexists with a non-wetting melt. However at energies very close to the melting point the icosahedral structure is replaced by a truncated decahedral structure which is almost fully wet by the melt. This structure remains until the cluster fully melts. The transition appears to be driven by a preference for the melt to wet the decahedral structure.

cond-mat.mtrl-sci↗