seminaire santoro

« High pressure physics: an introduction »

Mario Santoro, professeur invite, LENS, Florence, Italie,

High pressure physics (0.1-1000 GPa) is a broad research field, which came out through the last few decad and is now rapidly developing. I will give a short I will give a short overview of some of the most relevant aspects of this broad topic, mainly focused on simple systems. It will be first shown where extreme high pressure and temperature conditions are encountered in the universe, and how these conditions can severely affect the physics of dense materials, ultimately leading to intriguing phenomena such as metallization in normally dielectric systems and P induced superconductivity in elemental solids. I will briefly present on the high P phase diagram of some archetypical simple systems such as H₂, CO₂, phosphorous, and alkaline metals which include P induced molecular ordering, fluid-fluid phase transitions, polymerization, possible insulating-metal and metal insulating phase transitions. I will then talk on the main tool which is nowadays used for static high pressure experiments: the diamond anvil cell (DAC). Finally I will touch the point of how the DAC can be coupled to high temperatures devices such as ovens and laser heating set-up, as long as with characterization set up such as optical spectroscopy and X-ray scattering apparatus.