Dynamics and stability of icosahedral Fe-Pt nanoparticles

Abstract

The structure, dynamics and stability of Fe-Pt nanoparticles have been investigated using DFT-based techniques: total energy calculations and DFT molecular dynamics. The investigated systems included multi-shell and disordered nanoparticles of iron and platinum. The study is concerned with icosahedral particles with magic number of atoms (55): iron-terminated Fe${}_{43}$Pt${}_{12}$, platinum-terminated Fe${}_{12}$Pt${}_{43}$, and disordered Fe${}_{27}$Pt${}_{28}$. Additionally, the Fe${}_6$Pt${}_7$ cluster has been investigated to probe behaviour of extremely small Fe-Pt particles. Molecular dynamics simulations have been performed for a few temperatures between $T=150-1000$ K. The calculations revealed high structural instability of the Fe-terminated nanoparticles and a strong stabilising effect of the Pt-termination in the shell-type icosahedral particles. The platinum termination prevented disordering of the particle even at $T=1000$ K indicating very high melting temperatures of these Fe-Pt icosahedral structures. The analysis of evolution of the radial distribution function has shown significant tendency of Pt atoms to move to the outside layer of the particles -- even in the platinum deficient cases.

8 pages, 7 figures

References in corpus (2)

• The NumPy array: a structure for efficient numerical computation
• First principles calculations of the electronic and geometric structure of $A{g}_{27}C{u}_7$ nanoalloy

Cited by in corpus (1)

• Vibrational properties and stability of FePt nanoalloys