Melting of Materials at Extreme Pressure

This project will investigate the melting of various materials, primarily metals and alloys, under high pressure using diamond anvil cells (DACs) with both laser heating and resistive heating. Within DACs, materials can attain static compression pressures up to hundreds of GPa, and with heating techniques also temperatures of thousands of Kelvin. This enables the exploration

of melting curves at high pressure, thermal equations of state involving three variables (P-V-T). Understanding materials' behaviour under such conditions is important to potential engineering applications and planetary sciences as well as revealing physical insights into atomic bonding and electronic structure.

AWE has set out deliverables for the course of the project, which includes a list of materials to study (copper titanium 64, lead, lead-antimony, nickel, stainless steel, tantalum, titanium hydride, uranium, and vanadium), the use of DACs with small culet diamonds and toroidal DACs which increase the obtainable pressure, and with the aim of reaching up to 300 GPa and

3000 K. The first tasks will include developing and testing the resistive heating apparatus. Samples will be prepared and loaded into DACs in the lab in Edinburgh. Data will be collected from X-ray diffraction experiments conducted at synchrotrons in the UK (Diamond Light Source) and in Europe and the US, which have micro-focus X-rays.