Cryogenic High-Pressure System Integrated with On-Line Double-Sided Laser Heating and Raman Spectroscopy at GSECARS

A large number of high-pressure experiments experience problems resulting from unwanted chemical reactions and element diffusion, caused by a number of factors: carbon diffusion from diamond anvils and reaction with the sample; mass transport during laser heating; sample reaction with pressure medium or/and diamond anvils etc. Alkali metals, hydrogen and their compounds are the most challenging samples for diamond anvil cell experiments. For samples that contain hydrogen, the hydrogen can diffuse into the metal gasket and diamond anvils, resulting in anvil failure and making such experiments very expensive. One of the ways to suppress chemical reactions and diffusion is to keep the diamonds at cryogenic temperatures. In collaboration with DAC Tools we have developed a cryogenic high-pressure system with unique features. This system has membrane remote pressure control of the diamond anvil cell and is compatible with the on-line double-sided laser heating system at GSECARS [1] including off-line integrated optical instruments [2]. With this system we will be able to study minerals at temperatures down to 10 K and up to very high sample temperatures when coupled with double-sided laser heating. We can utilize high resolution x-ray diffraction techniques including single crystal and non-crystalline scattering (amorphous solids and molten fluids), as well as optical spectroscopy to study minerals properties in super-wide temperature range (10 - 6000 K) to provide new constrains on models for planetary evolution and origin. Details and future developments of cutting-edge techniques at GSECARS will be discussed.

[1] Prakapenka, V. et al. High Pressure Research. 28 (3), 225-235 (2008)

[2] Holtgrewe, N. et al. High Pressure Research. 39 (3), 457-470 (2019)