Grain boundary stabilization: thermodynamics or kinetics?

Two approaches have been proposed to slow down grain growth in nanocrystalline materials: the thermodynamic approach, which aims to reduce the grain boundary (GB) free energy, and the kinetic approach, which seeks to reduce GB mobility. Both approaches rely on GB segregation. We argue that the two approaches are inseparable, with one causing the other. The talk discusses the intricate relationships between GB phase transformations, GB diffusion, GB migration, and the recently proposed self-pinning mechanism.