Paper SS-TuP6
Topographical Changes of Liquid-Metal Alloys as a Function of Temperature

Tuesday, November 8, 2016, 6:30 pm, Room Hall D

Gallium-indium metal alloys are remarkable materials that, at the eutectic composition, are liquid at room temperature and form a very thin (0.7 nm) passivating oxide film on the surface. This makes them valuable in the field of molecular electronics as soft conformal electrical contacts and as, potentially, self-repairing wires. For this project, EGaIn is put through a fluidic shearing process that produces 3-layered core-shell nano/micro-spherical particles composed of a chemisorbed organic outer layer on an oxide film around the liquid metal core that prevents their coalescence. We used Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) to monitor topographical changes in these particles as a function of temperature. The liquid metal has a different rate of expansion from the oxide shell, and AFM coupled with SEM are especially well-suited to monitor these changes both as a function of the rate of change of the temperature and the thickness of the oxide film. The nature of the external coating can also be tuned through exposure of the particles to strong oxidants or shearing the metal in the presence of different surfactants. The effect of the different film coatings and the expansion of the particles upon application of heat will be discussed.