Reflectivity Studies on Nitrogen-Doped Lutetium Hydride at High Pressure

The optical studies of materials are a fundamentally important measurement to understand the nature of an insulator to metal transition and superconducting energy gap. Here we report reflectivity studies of a gasket material (rhenium) as a function of pressure by taking silver as a reference inside a diamond anvil cell (DAC) to overcome the diamond absorption. We also show that knowledge of the rhenium reflectivity can be used to calculate reflectivity of a sample inside a DAC. The Nitrogen-doped lutetium hydride is a rare-earth hydride which undergoes a dramatic color change and conductivity properties under pressure. In this work, we measure the absolute reflectivity of N-doped lutetium hydride under pressure and fit Drude-Lorentz mathematical models to these reflections.