Liquid metal (LM) alloys are an interesting and emerging technology that holds a large potential in various applications. LM systems houses a sea of electrons in which holds potential in electronic based areas.1 For example, gallium-based alloys had widely been utilised in stretchable electronics and sensor-based technology research to date.1, 2 But what differentiates their uses depends entirely on their surface area and alloy, where higher surface area materials i.e. LM nanodroplets would be fantastic in catalytic based research.3 However, limitations arise when attempting to increase the surface area with intermetallic based alloyed materials. Hence, this project reveals that planet-like nanodroplets are achievable such that they form an oxide crust, LM mantel, alongside an intermetallic core. Previously, synthesising these planet-like structures had been difficult, this is because of the lack of understanding in phase diagrams and how intermetallic cores form.4 But what we did was change that concept around and followed what the phase diagram explains, herewith a new methodology was developed where the core like intermetallic would dissolve homogenously allowing for complete dissolution when breaking up the bulk. From here, the planet-like structures for Cu-Ga were characterised and confirmed with various transmission electron microscopy (TEM) techniques, revealing how the cores are constrained by their boundaries, the concentration is representative of the bulk, the crystal phase corresponds to the intermetallic, and electron energy loss spectroscopy (EELS) demonstrating a metallic state. With the first system acting as a comparison, more planet-like systems were explored to prove versatility. As such, heating up the alloy in association to the phase diagram demonstrates a large increase in core like nanodroplets. From this interesting new concept, it is believed that more fundamental studies can be undertaken in figuring out how metallic based materials interact with one another. Already it had been demonstrated that metallic cores are present in numerous systems, and how this can demonstrate a blank gallium nanodroplet can be engineered.
About the presenter
Caiden Parker is an RMIT PhD student with CI Torben Daeneke. His research project relates to liquid metal fundamentals, as part of FLEET’s Enabling Technology A, Atomically-thin Materials.