Mechanisms of Interparticle Bridging in Sintering of Dispersed Nanoparticles

TL;DR

This paper models the initial formation and evolution of interparticle bridges during sintering of dispersed nanoparticles, revealing mechanisms and stability factors influencing the process.

Contribution

It introduces a kinetic Monte Carlo model to analyze neck formation mechanisms and stability in nanoparticle sintering, explaining experimental observations.

Findings

Neck initiation occurs via layering or clustering.

Stability depends on particle size ratios.

Bimodal size distributions enhance sintering.

Abstract

We model within the kinetic Monte Carlo method the initiation of neck formation and then later evolution of the resulting bridging regions for configurations involving small particles initially positioned fitted between large particles for situations typical for sintering of FCC nanocrystals, e.g., noble-metal nanoparticles. Neck initiation mechanisms by layering or clustering are identified. The stability of the resulting bridging configurations depends on several parameters, notably, on the relative small to large particle size ratio, and we explain recent experimental findings on improved sintering achieved for certain bimodal size distributions.