| AVS 66th International Symposium & Exhibition | |
| Chemical Analysis and Imaging Interfaces Focus Topic | Wednesday Sessions |
| Session CA+NS+SS+VT-WeA |
| Session: | Chemical Analysis and Imaging of Liquid/Vapor/Solid Interfaces I |
| Presenter: | Meng Jia, University of Delaware |
| Authors: | M. Jia, University of Delaware J.T. Newberg, University of Delaware |
| Correspondent: | Click to Email |
Liquid metals (LMs) have a combination of high thermal/electrical conductivity and excellent deformability. The application of LMs in the field of electronics has identified many opportunities for their use as stretchable electronics, self-healing conductors and interconnects. Gallium-Indium eutectic (EGaIn) is one of the leading alternatives to toxic liquid mercury because of its low vapor pressure, low viscosity, low toxicity and high conductivity. A surface oxide layer is known to form when EGaIn is exposed to ambient conditions. However, surface sensitive measurements of this chemistry occurring under ambient conditions are strongly lacking. Herein we present results from the interaction of oxygen and water vapor with the liquid-gas interface of an EGaIn droplet deposited on an W foil using ambient pressure X-ray photoelectron spectroscopy (AP-XPS). EGaIn was examined up to a maximum of 1 Torr pressure at 550 K. Results reveal that under ambient conditions both oxygen and water vapor form a Ga(3+) oxide (Ga2O3) as an outer layer, while a thin layer of Ga(1+) oxide (Ga2O) resides between metallic EGaIn and the outer Ga(3+) oxide. Both gases were unreactive towards Indium under our experimental conditions. The oxidation kinetics in the presence of water vapor were much faster compared oxygen. Proposed reaction mechanisms will be discussed.