High pressure kinetics
Materials behave differently depending on pressure and temperature as well as the rates of compression and cooling. For example, shock-induced chemistry often results in small grains or even nanoparticles of dissociated products, whereas static compression typically leads to large grains or even single crystals of associative products. Materials transform displacively at defects or along shear planes under shock compression, but diffusively at the interface under static compression. In order to gain insights of detailed material behaviors and transformations, we adapt a wide range of high pressure technologies which include both conventional static and dynamic high pressure methods, as well as recently developed dynamic-DAC.
High-speed optical microscope images of dendritic ice VI crystals grown in d-DAC.
This project is currently funded by ACS-PRF (49207-ND10) for High Pressure Kinetic Studies of Formation, Phase Transition, and Crystal Growth of Methane Hydrates in Dynamic-DAC.
References:
- Dynamic pressure-induced growth of ice VI: Observation of Dendrite Growth and Shock Crystal Growth, Geun-woo Lee, William Evans, Choong-Shik Yoo, Pro. Nat. Acad. Sci. 104, 9178 (2007).
- Dynamic Diamond Anvil Cell (dDAC): A Novel Device for Studying the Dynamic-Pressure Properties of Materials, William J. Evans, Choong-Shik Yoo, Geun Woo Lee, Hyunchae Cynn, Magnus J. Lipp and Ken Visbeck, Rev. Sci. Instrum. 78, 073904 (2007).
- Evidence for Ice VII-like Order of High Density Water in Dynamic Diamond Anvil Cell, Geunwoo Lee, William Evans, Choong-Shik Yoo, Phys. Rev. B 74, 134112 (2006).