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Department of Chemistry Choong-Shik Yoo

Yoo, Choong-Shik


Professor of Chemistry and Institute of Shock Physics

Fulmer 549 & Shock Physics 242
Pullman, WA 99164


(509) 335-2712


Post-Doctoral Study, 1986-1989
Washington State University, Pullman, WA


Ph.D. Physical Chemistry, 1986
University of California, Los Angeles, CA


Professor Yoo received his Ph.D. in Physical Chemistry in 1986 from UCLA and then spent three years at WSU as a Postdoctral Research Fellow. In 1989, he joined the Lawrence Livermore National Laboratory where he led a large multi-disciplinary research group for High Pressure Physics Program. After a long career at the national laboratory, in 2007 he returned to WSU as a new faculty member at the Chemistry Department and the Institute for Shock Physics. Professor Yoo won twice in 1995 and 2006 the DOE awards for Excellence in Weapons Materials Research. He currently serves as US Regional Editor for High Pressure Research, and is a member of American Chemical Society, American Physical Society, American Geophysics Union, and Materials Research Society.Our group focuses on Extreme Materials Research at the pressure-temperature conditions of the Earth’s and Joviant planetary interiors, where materials alter their properties in many fundamental ways and, thus, provide exciting opportunities for one to discover new materials, novel phenomena, and exotic states of matter- not present at the ambient condition. Examples are numerous, including recently discovered stishovite-like carbon dioxide polymer, metallic hydrogen, superconducting lithium, superionic water, novel metal nitrides, superionic lithium nitrides, and many others. High-pressure research will ultimately establish a new Periodic Table of the elements and compounds with completely redefined chemical and physical properties. Our extreme materials research helps unveil such a new materials order and understand its governing rules.Our research utilizes modern static and dynamic high-pressure technologies coupled with the state-of-the-art laser spectroscopy and the x-ray diffraction and x-ray spectroscopy at national synchrotron facilities. Because materials often behave differently under static and dynamic compressions, we emphasize an integrated approach of static and dynamic experiments over extended ranges of pressure, temperature, and strain rate.Materials of our research interest range from fundamental materials of quantum solids, molecular solids, covalent and ionic solids, and f-and d-electron metals to functional materials such as reactive nanoparticles, hydrogen storage materials, strongly correlated systems, and high energy density solids. Because of its multi-disciplinary nature of high-pressure materials research, we often collaborate with theorists and scientists well beyond our group and Chemistry department, including Institute for Shock Physics, Materials Science Program, and National Laboratories.


Reversible Photochemical Transformation of S and H2 Mixture to (H2S)2H2 at High Pressures, Sakun Duwal and Choong-Shik Yoo, J. Phys. Chem. C (2017) in print; DOI: 10.1021/acs.jpcc.7b00549;

New States of Matter and Chemistry at Extreme Pressures: Low-Z Extended Solid, Choong-Shik Yoo, Mat. Res. Soc. Bull. (2017) in print;

Hydrogen-doped polymeric carbon monoxide at high pressure, Young-Jay Ryu, Choong-Shik Yoo, Minseob Kim, Xue Yong, John Tse, Sungkeun Lee, Eun Jeong Kim, J. Phys. Chem. C 121, 10078 (2017).;

Phase diagram of carbonyl sulfide: an analogy to carbon dioxide and carbon disulfide, Choong-Shik Yoo, Sakun Duwal, Minseob Kim, and Yasuo Ohishi, J. J. Appl. Phys. 56, 05FA04 (2017).;

Solid-State Polymerization of CO2 from Catalytic Photoexcitation: An Molecular Dynamic Study, Xue Yong, John Tse, and Choong-Shik Yoo, J. Phys. Chem. C. 120, 27548 (2016). DOI: 10.1021/acs.jpcc.6b10157 ;

Dense Carbon Monoxide to 160GPa: Stepwise polymerization to two-dimensional layered polymer, Young-Jay Ryu, Ranga P. Dias, Dennis Klug, Minseob Kim, and Choong-Shik Yoo, J. Phys. Chem. C (2016) DOI: 10.1021/acs.jpcc.6b09434;

Phase transformations and symmetrization of dense D2S, Sakun Duwal and Choong-Shik Yoo, J. Phys. Chem. C 120, 21770 (2016).;

Intercalation of solid hydrogen into graphite under pressures, Jinhyuk Lim and Choong-Shik Yoo, Appl. Phys. Lett., 109, 051905 (2016).;

Pressure-induced phase and chemical transformation of lithium peroxide (Li2O2), Mihindra Dunuwille, Minseob Kim, and Choong-Shik Yoo, J. Chem. Phys. 145, 084701 (2016).

Pressure-induced transformation of dense carbonyl sulfide to singly bonded amorphous metallic solid, Minseob Kim, Ranga Dias, Yasuo Oishi, Takehiro Matsuoka, Jing-Yin Chen, and Choong-Shik Yoo, Sci. Rep. 6, 31594 (2016); DOI:10.1038/srep31594

Phase Diagram of Ammonium: Raman Spectroscopic Constraints at High Pressures and Temperatures, Mihindra Dunuwille and Choong-Shik Yoo, J. Chem. Phys. 144, 244701 (2016).

Crystal structures and dynamical properties of dense CO2, Xue Yong, Hanyu Liu, Min Wu, Yansun Yao, John S. Tse, Ranga Dias, and Choong-Shik Yoo, Proc. Nat. Acad. Sci. 113, 11110 (2016); DOI:10.1073/pnas.1601254113.

Structural phase transitions and metallization of GeS at high pressures, Ranga Dias, Minseob Kim and Choong-Shik Yoo, J. Phys. Rev. B 93, 104107 (2016).

Shear-induced isostructural phase transition and metallization of layered tungsten disulfide under non-hydrostatic compression, Sakun Duwal and Choong-Shik Yoo, J. Phys. Chem. C 120, 5101 (2016).

Phase Transitions in I2O5 at High Pressures: Raman and X-ray Diffraction Studies, Monseob Kim and Choong-Shik Yoo, Chem. Phys. Lett., 648, 13 (2016).