Sintering Dynamics of Different-Sized Cu-Ag Core-Shell Nanoparticles under Various Temperature
Jiaqi Wang
Department of Mechanical, Aerospace and Biomedical Engineering, University of Tennessee-Knoxville
This page visualizes the sintering process of two Cu-Ag core-shell nanoparticles at 300 K. Different sintering mechanisms are unraveld, such as reorientation, plastic deformation, surface diffusion, crystallization-amorphization-recrystallization. The animation is made by Jiaqi Wang, a graduate student from Nanoscale Heat Transfer Lab in Department of Mechanical, Aerosapce and Biomedical Engineering.
Understanding of nanoparticle (NP) sintering mechanism in atomic scale is of significance for improving various NP applications, such as printable nanoinks, catalysts and electrode materials in energy devices. In this research, sintering dynamics of Cu-Ag core-shell NPs with various geometries is investigated through molecular dynamics simulations under different temperatures. The evolutions of local crystalline structure and potential energy during the sintering of two NPs are characterized using the common neighbor and structural deformation analyses. Sintering of two equal-sized NPs are divided into three stages according to shrinkage evolution, and depending on sintering stage and condition, NP undergoes reorientation for achieving epitaxial layers, plastic deformation, surface diffusion, wetting and, crystallization-amorphization-recrystallization. Although the Cu core is not coalescent during solid state sintering, nor in surface-premelting induced sintering, it enhances the mobility of Ag shell atoms, thus increasing the bonding strength.
Color Legend: posted: April 2016.Sintering process
updated: April 2016.