A molecular dynamics study of the effect of the substrate on the thermodynamic properties of bound Pt-Cu bimetallic nanoclusters.

Abstract

In this work confinement of the Pt708Cu707 bimetallic nanocluster in single-walled carbon, boron nitride, and silicon carbide nanotubes was investigated using molecular dynamics simulation. The results of the calculations showed that at 50% composition, a eutectic-like behavior is seen during the melting-freezing process. Also, the Pt708Cu707 bimetallic nanocluster tends to have a core-shell like structure with a Pt-rich core and a Cu-rich shell, except for boron nitride nanotubes in which the nanocluster exhibits a completely different pattern on the tube wall. The Pt-Cu nanoclusters confined in boron nitride nanotubes are extremely extended on the tube wall in such a way that most of the nanotube-nanocluster interface is covered by a monolayer metal coating which can promise unique physical and chemical properties for these types of nanocomposites. Also, extension of the nanocluster on the substrate surface reduces its melting point.