College 1 Seminar | Experimental and computational investigation of the atomic behaviours and complex structures within liquid metal systems

Liquid metals (LMs) are emerging as an interesting class of solvent, which have found application in 2D materials synthesis, energy storage media, and biological applications, among others. The definition of LMs is broad, however, in general they are metals which remain fluidic at temperatures below 500°C. Room temperature liquid metals (RTLMs), such as gallium, tin, and indium, and their eutectic alloys, are a subset of these metals, which remain liquid ≤60°C, and have recently gained wide scientific and industrial attention. These liquid metal materials have a thin oxide layer, which has been extensively studied. However, the thin oxide layer, combined with the free-flowing electrons within the LM, renders the bulk LM opaque to state-of-the-art techniques, such as Raman and FTIR. As such, almost nothing is known about the structural arrangements of the metal atoms within a LM at or near interfaces. Therefore, in order to understand the behaviours and structures within the bulk LM, different and new techniques must be employed to probe the LM systems.

In this seminar, Pierre will speak about his, and the larger Liquid Metals team at RMITs, investigations into these LM systems, which have employed a wide range of techniques, including Atomic Force Microscopy (AFM), Tunnelling Electron Microscopy (TEM), Molecular Dynamics (MD) Simulations and neutron scattering techniques, such as (Ultra) Small Angle Scattering ((U)SANS) and Neutron Reflectometry (NR). By combining these techniques, they have found that these LM systems are more complex than originally thought, with certain LM alloys exhibiting atomic aggregation, intermetallic structures, chain-like arrangements and colloidal suspensions. Pierre will discuss how the various techniques have been utilised to understand these structures and atomic arrangements which form within the bulk LM. Different LM systems, ranging from pure gallium to its eutectic and non-eutectic alloys, and domains, ranging from nano-, micro- and macroscale geometries, have been investigated, providing a deeper understanding into how these structures and arrangements evolve within the bulk LM solvent.

Pierre is a third year PhD student in the school of Applied Chemistry at RMIT university. He completed his Undergraduate and Masters in the field of Physics at the University of Melbourne. His project aims to probe and understand the behaviours and structures within liquid metal systems near the liquid metal-oxide interface, using AFM, MD simulations and neutron-based techniques. During his PhD, he has also worked as a research assistant, where he helped with an industry-based project investigating the use of liquid metals in batteries and energy storage media. He hopes to continue his academic journey after completing his PhD.