Stretching the threshold of reversible dynamics in silicon clusters: A case of carbon alloyed Si-6

摘要

Silicon clusters with 3-50 atoms undergo isomerization/reversible dynamics or structural deformation at significantly lower temperatures of 350 K-500 K. Through Born Oppenheimer Molecular Dynamical (BOMD) simulations, the current study demonstrates that carbon alloying enhances the thermal stability of a silicon cluster. The study is carried out on a Si-6 cluster which has been recently reported to undergo reversible dynamical movements using aberration-corrected transmission electron microscopy. Present BOMD simulations validate the experimentally observed reversible atomic displacements (reversible dynamical movements) at finite temperatures which are seen to persist nearly up to 2000 K. Carbon alloying of Si-6 is seen to stretch the threshold of reversible dynamics from 200 K to 600 K depending upon the alloying concentration of carbon in the cluster. Published by AIP Publishing.