Edge-to-bulk thermodynamic convergence of melting in GaN nanoribbons

Abstract

The melting behavior of GaN nanoribbons was investigated using molecular dynamics simulations with particular emphasis on the emergence of edge-to-bulk thermodynamic convergence. Convergence analysis based on edge energy demonstrated that the representative nanoribbon configuration with a width of 353.421 Å is sufficiently large to reproduce the intrinsic thermal behavior of the system. Thermodynamic and structural analyses of representative nanoribbons revealed a melting transition near 4100 K accompanied by the loss of crystalline order. The results showed that melting initiates preferentially at the free zigzag boundaries and subsequently propagates toward the interior region. A critical Lindemann threshold of 0.0715 was identified for distinguishing solid-like and liquid-like atomic environments. Additional holding, heating-rate, size-effect, and heating–cooling simulations further confirmed the thermodynamic stability of the observed transition. Although small kinetic and finite-size effects were observed, the apparent melting temperature remained close to 4100 K under all investigated conditions.