Molecular Dynamics Study of Coalescence Behavior of InGaN Nanoparticles in Homogeneous and Heterogeneous Phase by Sintering

Abstract

Sintering, a thermally activated consolidation process, densifies discrete particles into continuous structures via atomic-scale mass transport below the melting point. Here, we employ large-scale molecular dynamics (MD) simulations to systematically elucidate the coalescence and neck growth mechanisms of In₀.₁Ga₀.₉N nanoparticles in both homogeneous wurtzite–wurtzite and heterogeneous wurtzite–zincblende phase configurations. Simulations were conducted using the Stillinger–Weber1 potential across nanoparticle pairs of varying size and temperatures (Fig. 1). Mean-squared displacement analysis reveals enhanced diffusivity in Zb-phase atoms, while heterogeneous systems exhibit higher shrinkage ratios that intensify with particle size reduction. Common neighbor analysis indicates a pronounced Wz phase transformation in Zb nanoparticles below 25 Å, accompanied by microcrystalline Wz domains on larger Zb surfaces. Dislocation extraction analysis2 further identifies defect evolution within the neck. The neck growth kinetics adheres to a power-law relation with time, consistent with classical sintering theory3, thereby validating the atomistic modelling.