Self-assembly, interrupted: synthesizing metastable structures by inducing solid–solid phase transformations

Solid–solid phase transformations are powerful yet difficult-to-study phenomena in a wide range of materials system, and they remain under-utilized in the assembly design of mesoscale materials despite their ubiquity in nature. Here, we alchemically induce such phase transformations by changing the pair interactions of isotropic particles mid-molecular dynamics simulation. Our computational model systems are multi-well isotropic pair potentials that are tuned to self-assemble a variety of crystal structures. By varying the temperature and configuration at which the potential is changed, we observe a wide variety of assembly behavior, including the formation of both metastable polymorphs as well as previously kinetically inaccessible, stable polymorphs. Our findings lay out a blueprint for utilizing solid–solid phase transformations in targeting the assembly of specific structures via experimentally feasible design levers.