Dec.21th, Prof. Alexander Goncharov, winner of “2015 People's Republic of China Friendship Award”, gave a work report entitled "Research at High Pressures with Diamond Anvil cells: Implications For Planetary Interiors, to Quantum Phenomena In Dense Systems and Synthesis of Novel Materials” to ISSP researchers.
In the talk, he introduced recent developments in diamond anvil cell (DAC) research: (1) a progress of achieving ultrahigh pressures approaching 1 TPa using a double stage diamond anvil technique; (2) A pulsed laser heating technique allows measurements of structural and optical properties of materials at P-T conditions exceeding 200 GPa and 10000 K; (3) The use of ultrafast laser sources enables a number of new single-shot and pump-probe dynamic and static compression experiments. He presented new data on ultrafast compression of deuterium statically precompressed up to 55 GPa, optical properties of hydrogen up to 140 GPa and 3000 K, and thermal conductivity measurements of Fe under the Earth’s core conditions. Chemistry rules change with pressure making more stable materials with modified chemical bonding and varied stoichiometry (eg. new chlorides, hydrides and other materials). Finally, He reported on the study of high-pressure chemistry in the H-S system that has been recently shown to reveal decomposition (~150 GPa) and superconductivity (at >200 K).
In the future, he will perform experiments utilizing the latest achievements in fast laser techniques to elucidate a putative behavior of hydrogen at the transition to metallic and superconducting state. These results are significant for understanding of planetary interiors, physics and chemistry of materials at extreme conditions, and synthesis of materials with extraordinary properties for new technologies.
Prof. Alexander Goncharov in the presentation (Image by WANG Yuan)