Geochemistry Department Staff

Vita

Randall Cygan received his Ph.D. degree in 1983 (Dissertation title: Chemical Diffusion and Dielectric Polarization Processes in Silicate Minerals). In 1983 he joined the Geochemistry Department of Sandia National Laboratories in Albuquerque, New Mexico where presently he is a senior member of the technical staff. He also spent two years as an assistant professor in the Geology Department at the University of Illinois in Urbana, Illinois (1987-1988). His research interests are varied, including investigations of mineral equilibria, chemical kinetics, surface chemistry of minerals, sorption and dissolution of minerals, shock metamorphism, and atomistic modeling of minerals and geochemical processes. Randall Cygan has published extensively in various geological, chemical, and materials science journals, and has received numerous honors including membership in Phi Eta Sigma and Phi Kappa Phi honor societies. He is a Centennial Fellow of the College of Earth and Minearal Science at Pennsylvania State University. He is also a member of the American Chemical Society, the American Geophysical Union, the Geochemical Society, the Materials Research Society, and the Mineralogical Society of America.

Selected Publications

• Cygan, R. T. (1998) Molecular models of metal sorption on clay minerals. In J. D. Kubicki and W. F. Bleam, Eds., Molecular Modeling of Clays, The Clay Minerals Society, Boulder, in press.
• Fisler, D. K. and Cygan, R. T. (1998) Diffusion of calcium and magnesium in calcite. American Mineralogist, in press.
• Fisler, D. K., Gale, J. D., and Cygan, R. T. (1998) A shell model for the simulation of rhombohedral carbonate minerals and their point defects. American Mineralogist, in press.
• Nagy, K. L., Cygan, R. T., Hanchar, J. M., and Sturchio, N. C. (1998) Gibbsite growth kinetics on gibbsite, kaolinite, and muscovite substrates: AFM evidence for epitaxy and an assessment of reactive surface area. Geochimica et Cosmochimica Acta, in press.
• Brady, P. V., Cygan, R. T., and Nagy, K. L. (1998) Surface charge and metal sorption to kaolinite. In E. A. Jenne, Ed., Adsorption of Metals by Geomedia, Academic Press, San Diego, 371-382.
• Brinker, C. J., Ashley, C. S., Sellinger, A. S., Cygan, R. T., Nagy, K. L., Assink, R., Alam, T., Rao, S., Prabakar, S., and Scotto, C. S. (1998) Sol-gel preservation of mankind’s cultural heritage in objects constructed of stone. Sandia National Laboratories Report, SAND98-0251, 36 pp.
• Cygan, R. T., Nagy, K. L., and Brady, P. V. (1998) Molecular models of cesium sorption on kaolinite. In E. A. Jenne, Ed., Adsorption of Metals by Geomedia, Academic Press, San Diego, 383-399.
• Cygan, R. T., Westrich, H. R., and Doughty, D. H. (1998) Molecular dynamics study of lithium diffusion in lithium-manganese spinel cathode materials. In D. S. Ginley et al., Eds., Materials for Electrochemical Storage and Conversion II — Batteries, Capacitors and Fuel Cells, Materials Research Society, Pittsburgh, 109-114.
• Fisler, D. K. and Cygan, R. T. (1998) Cation diffusion in calcite: Determining closure temperatures and the thermal history for the ALH84001 meteorite. Meteoritics and Planetary Science, 33, 785-789.
• Hartzell, C. J., Cygan, R. T., and Nagy, K. L. (1998) Molecular modeling of the tributyl phosphate complex of europium nitrate in the clay hectorite. Journal of Physical Chemistry, 102, 6722-6729.
• Myers, S. A., Cygan, R. T., Assink, R. A., and Boslough, M. B. (1998) 29 Si MAS NMR relaxation study of shocked Coconino sandstone from Meteor Crater, Arizona. Physics and Chemistry of Minerals, 25, 313-317.
• Schwandt, C. S., Cygan, R. T., and Westrich, H. R. (1998) Magnesium self-diffusion in orthoenstatite. Contributions to Mineralogy and Petrology, 130, 390-396.
• Westrich, H. R., Brady, P. V., Cygan, R. T., Gruenhagen, S. E., Anderson, H. L., and Nagy, K. L. (1998) Characterization of retardation mechanisms in soil. U.S. Nuclear Regulatory Commission Report, NUREG/CR-6603 and SAND98-0419, 23 pp.
• Boyle, T. J., Al-Shareef, H. N., Buchheit, C. D., Cygan, R. T., Dimos, D., Rodriguez, M. A., Scott, B., and Ziller, J. W. (1997) Non-traditional solution routes to ferroelectric materials. Integrated Ferroelectrics, 18, 213-223.
• Cygan, R. T. (1997) Book review of Chemical Fundamentals of Geology by Robin Gill. Journal of Geoscience Education, 45, 285-286.
• Hobbs, J. D., Cygan, R. T., Nagy, K. L., Schultz, P. A. , and Sears, M. P. (1997) All-atom ab initio minimization of the kaolinite crystal structure. American Mineralogist, 82, 657-662.
• Kirkpatrick, R. J, Kim, Y., Weiss, C. A., and Cygan, R. T. (1997) NMR spectroscopic investigations of surface and interlayer species on minerals, clays and other oxides. In A. Gonis et al., Eds., Properties of Complex Inorganic Solids, Plenum Press, New York, 157-168.
• Nagy, K. L., Cygan, R. T., Brinker, C. J., and Sellinger, A. (1997) Protective coatings for concrete. Sandia National Laboratories Report, SAND97-2940, 2 pp.
• Nagy, K. L., Cygan, R. T., Scotto, C. S., Brinker, C. J., and Ashley, C. S. (1997) Use of coupled passivants and consolidants on calcite mineral surfaces. In P. B. Vandiver et al., Eds., Material Issues in Art and Archaeology V, Materials Research Society, Pittsburgh, 301-306.
• Westrich, H. R., Brady, P. V., Cygan, R. T., Nagy, K. L., and Anderson, H. L. (1997) Metal sorption on kaolinite. Proceedings of the Low-Level Radioactive Waste Management Conference, 18, 2.12.
• Brady, P. V., Cygan, R. T., and Nagy, K. L. (1996) Molecular controls on kaolinite surface charge. Journal of Colloid and Interface Science, 183, 356-364.
• Cygan, R. T. (1996) Shock therapy: How Earth responds to impacts from outer space. Earth in Space, 9, 7-8,14.
• Cygan, R. T., Crossey, L. J., and Marin, L. E. (1996) Researchers focus on Earth’s response to hypervelocity impacts. Eos, 77, 197,199.
• Kim, Y., Cygan, R. T., and Kirkpatrick, R. J. (1996) 133Cs NMR and XPS investigation of cesium adsorbed on clay minerals and related phases. Geochimica et Cosmochimica Acta, 60, 1041-1052.
• Kim, Y., Kirkpatrick, R. J. , and Cygan, R. T. (1996) 133Cs NMR study of cesium on the surfaces of kaolinite and illite. Geochimica et Cosmochimica Acta, 60, 4059-4074.
• Schwandt, C. S., Cygan, R. T., and Westrich, H. R. (1996) Calcium self-diffusion in grossular garnet. American Mineralogist, 81, 448-451.
• Cygan, R. T., Westrich, H. R., and Doughty, D. H. (1995) Ionic modeling of lithium manganese spinel materials for use in rechargeable batteries. In D. H. Doughty et al., Eds., Materials for Electrochemical Storage and Conversion — Batteries, Capacitors and Fuel Cells, Materials Research Society, Pittsburgh, 113-118.
• Kim, Y., Kirkpatrick, R. J., and Cygan, R. T. (1995) 133Cs NMR study of Cs reaction with clay minerals. In V. Jain and R. A. Palmer, Eds., Environmental Issues and Waste Management Technologies in Ceramic and Nuclear Industries, American Ceramic Society, Columbus, 629-636.
• Levy, S. C., Lagasse, R. R., Cygan, R. T., and Voigt, J. A. (1995) Lithium ion rechargeable systems studies. In A. S. Wolsky, Ed., Proceedings of the Twelfth International Seminar on Primary and Secondary Battery Technology and Application, Ansum Enterprises, Boca Raton, 1-5.
• Schwandt, C. S., Cygan, R. T., and Westrich, H. R. (1995) Mg self-diffusion in pyrope garnet. American Mineralogist, 80, 483-490.
• Westrich, H. R., Cygan, R. T., Brady, P. V., Nagy, K. L., Anderson, H. L., Kim, Y., and Kirkpatrick, R. J. (1995) The sorption behavior of Cs and Cd onto oxide and clay surfaces. In Proceedings of the Waste Management Conference, WM’95, 24-4.
• Assink, R. A., Boslough, M. B., and Cygan, R. T. (1994) Characterization of amorphous material in shocked quartz by NMR spectroscopy. In S. C. Schmidt et al., Eds., High-Pressure Science and Technology - 1993, American Institute of Physics, 383-386.
• Assink, R. A., Boslough, M. B., and Cygan, R. T. (1994) Power-law relaxation of spin-1/2 nuclei in solids. Journal of Magnetic Resonance, A106, 116-118.
• Boslough, M. B., Cygan, R. T., Assink, R. A., and Kirkpatrick, R. J. (1994) NMR characterization of shocked quartz. In M. Kamo et al., Eds., Proceedings of the NIRIM International Symposium on Advanced Materials ‘94, National Institute for Research in Inorganic Materials, 211-216.
• Cygan, R. T. and Boslough, M. B. (1994) Analysis of experimentally shocked minerals by NMR spectroscopy. Sandia National Laboratories Report, SAND94-0294, 97 pp.
• Cygan, R. T. and Boslough, M. B. (1994) Application of NMR shock barometer to naturally shocked minerals. Sandia National Laboratories Report, SAND94-1497, 33 pp.
• Cygan, R. T., Boslough, M. B., and Kirkpatrick, R. J. (1994) NMR spectroscopic examination of shocked sandstone from Meteor Crater, Arizona. In S. C. Schmidt et al., Eds., High-Pressure Science and Technology - 1993, American Institute of Physics, New York, 807-810.
• Schwandt, C. S., Cygan, R. T., and Westrich, H. R. (1993) A thin film approach for producing mineral diffusion couples. Pure and Applied Geophysics, 141, 631-642.
• Westrich, H. R., Cygan, R. T., Casey, W. H., Zemitis, C., and Arnold, G. W. (1993) The dissolution kinetics of mixed-cation orthosilicate minerals. American Journal of Science, 293, 869-893.
• Cygan, R. T. and Carrigan, C. R. (1992) Time-dependent Soret transport: Applications to brine and magma. Chemical Geology, 95, 201-212.
• Cygan, R. T. and Jarrell, G. D. (1992) Thermal diffusion processes in aqueous sodium chloride solutions. Sandia National Laboratories Report, SAND92-1275, 36 pp.
• Cygan, R. T., Boslough, M. B., and Kirkpatrick, R. J. (1992) NMR spectroscopy of experimentally shocked quartz and plagioclase feldspar powders. In G. Ryder and V. L. Sharpton, Eds., Proceedings of the 22^nd Lunar and Planetary Science Conference, Lunar and Planetary Institute, Houston, 127-136.
• Cygan, R. T., Boslough, M. B., and Kirkpatrick, R. J. (1992) NMR spectroscopy of experimentally shocked silicate minerals. In S. C. Schmidt et al., Eds., Shock Compression of Condensed Matter - 1991, Elsevier, Amsterdam, 633-636.
• Cygan, R. T. (1991) The solubility of gases in NaCl brine and a critical evaluation of available data. Sandia National Laboratories Report, SAND90-2848, 99 pp.
• Cygan, R. T., Boslough, M. B., and Kirkpatrick, R. J. (1990) NMR spectroscopy of experimentally shocked quartz: Shock wave barometry. In V. L. Sharpton and G. Ryder, Eds., Proceedings of the 20^th Lunar and Planetary Science Conference, Lunar and Planetary Institute, Houston, 451-457.
• Cygan, R. T., Boslough, M. B., and Kirkpatrick, R. J. (1990) Experimentally shocked quartz, NMR spectroscopy, and shock wave barometry. In S. C. Schmidt et al., Eds., Shock Compression of Condensed Matter - 1989, North-Holland, Amsterdam, 653-656.