Complexity and Opportunities in Liquid Metal Surface Oxides

The ability of metal alloys to rapidly oxidize in ambient conditions presents both a challenge and an opportunity. Herein, we focus on opportunities buried in the passivating oxide of liquid metal particles. Recently described subsurface complexity and order present an opportunity to frustrate homogeneous nucleation and, hence, enhanced undercooling. The plasticity of the underlying liquid metal surface offers an autonomously repairing subsurface hence, the lowest E-0 component dominates the surface unless stoichiometrically limited. This plasticity provides an opportunity to synthesize organometallic polymers that in situ self-assemble to high aspect ratio nanomaterials. An induced surface speciation implies that, under the appropriate oxidant tension, the oxide thickness and composition can be tuned leading to temperature-dependent composition inversion and so-called chameleon metals. The uniqueness of the demonstrated capabilities points to the need for more exploration of this small but rather complex part of a metal alloy.