Phase transitions in nanostructures

David Cobden
UW Physics

Because of the change in structure, the latent heat, and the need for nucleation, first-order phase transitions involving a solid phase tend to be very sensitive to inhomogeneities and difficult to study in bulk material. For solid-solid transitions the situation is particularly bad, with random domain formation, high strain, and fracture being almost unavoidable. I will discuss how working with nanoscale systems, which are small compared with the scale of inhomogeneities and domains, allows much improved control of such transitions. It also opens up possibilities to investigate phase transitions in reduced dimensionality, where the physics may be qualitatively different from that in three dimensions and may be more theoretically tractable as well. These advantages will be illustrated in two systems: a solid-solid transition driven by electron-electron correlations in a vanadium dioxide nanobeam; and vapor-liquid-solid transitions occurring in a monolayer of gas atoms adsorbed on a carbon nanotube.