Grant: Discovery Grants Program - Individual

Materials science involves the manipulation of atoms to fabricate materials with customized functionalities. Pressure and temperature can significantly alter the properties and induce phase transitions in materials that lead to novel functionalities. Similarly, pressure and temperature affect the structure and properties of minerals, which is vital in geology and earth sciences. The long-term goal of my research is to unravel the underlying physics and chemistry that govern the properties, structures and reactivity of matter under extreme environments. We utilize both experimental and theoretical approaches to investigate the underlying principles to set the foundation for guiding future explorations. The short-term goal is to expand our understanding of how changes in pressure and temperature impact bonding, structures, and chemical reactivity through the study of specific systems. We propose three projects in this DG application. [1] Electron topology of compressed binary alloys. We will study the evolution of electron density in binary alloys under compression. The aim is to evaluate the extent of electron transfer within the materials. The experimental results will be compared with theoretical calculations and subjected to analysis using established chemical bonding principles. The insights gained serve as the foundation for constructing a conceptual model employing the density-of-state moments theory to predict the stability of superconducting polyhydrides with the clathrate structures. [2] Structure and structural transformation in amorphous ices and the connection to liquid water. Despite extensive studies, surprises in the behaviour of water and ice continue to emerge. Contrary to the anticipated shift towards crystal-crystal transformation as ice is compressed at higher temperatures, we found a sudden reversal in this trend. Moreover, the diffraction of amorphous ice prepared from cryogenic co-deposition of water vapour and nitrogen revealed a pattern strikingly similar to medium-density ice, which was suggested to be the genuine solid state of water. We will utilize diffraction and vibration spectroscopy using synchrotron radiation and complemented by large-scale modelling to unveil the intricacies of formation and transformation processes in the amorphous states. [3] Investigate reactions between H2 and oxygen-containing minerals. The thermodynamic environment of Earth spans a considerable pressure and temperature range, rendering it a versatile chemical reactor. The research on the generation of indigenous water from anhydrous minerals is a topic of recent interest. We propose to study the reactions of H2 with prototypical minerals such as the carbonates, silicates and oxides minerals with first-principles molecular dynamics calculation under Earth-like conditions. The research may uncover new water sources, shed light on geological processes, and offer insights into the possibility of sustaining life in extreme conditions.