Grain Boundary Motion on Curved Substrate

TL;DR

This paper develops a simulation and analytical model to study how substrate curvature influences grain boundary mobility in 2D materials, revealing significant mobility enhancements and specific shape dependencies.

Contribution

It introduces a combined kinetic Monte Carlo and analytical approach to quantify the effects of substrate curvature on grain boundary kinetics.

Findings

GB mobility increases over 50 times with substrate shape changes

Mobility depends exponentially on amplitude and linearly on wave vector

The kinetic shape of GBs relates to substrate wave vector and amplitude

Abstract

Grain boundary (GB) kinetics is important for many applications in 2d materials and metal thin films. To study how the substrate shape affects GB mobility and kinetics, we develop a kinetic Monte Carlo (kMC) simulation method and an analytical model for GBs on the curved substrate by combining disconnection theory and by Foppl von Karman equations. Using sinusoidal MoS2 as an example, we can increase its GB mobility more than 50 times by changing substrate shape amplitudes and periods. We find that amplitude change GB mobility exponentially while wave vector change GB mobility linearly. The sinusoidal GB kinetic shape has wave vector twice as substrate and amplitude proportional to substrate squared amplitude.