The application spectrum of liquid metals as solvents in crystal synthesis is fast expanding. Harnessing liquid metal-mediated crystal growth with high spatial resolution is essential for the precise micro/nanopatterning of functional crystals. However, crystal growth under boundary confinement and postgrowth crystal evolution driven by solid-phase diffusion remains underexplored. Here, we investigate the evolution of AuGa2 intermetallic crystals formed by touch transfer of a liquid Ga layer onto lithography-patterned Au thin films. We demonstrate postgrowth coarsening of the as-grown AuGa2 crystals via Ostwald ripening, sustained by mass transport through a solid Ga phase. Three-month observations reveal that this ripening is a long-term effect that progressively diminishes over time. Pattern width and edge features are found to modify the local Ga/Au thickness, shifting phase equilibrium and thereby tuning crystal size and spatial distribution. These findings provide mechanistic insight for the precise control of crystal growth and patterning in liquid metal synthesis systems.
Johnston et al. (Mon,) studied this question.