I. Thermomechanical Extremes

GOAL: To enhance understanding of materials in extreme conditions by advancing the evolving synergy between static, quasi-static, and dynamic compression techniques over a broad range of strain and strain rates in close synergy with theory, modeling, and simulation.

REPRESENTATIVE PUBLICATIONS: Heading link

DFT
DFT-MD predicted shock-ramp of (Mg0.75Fe0.25)O with low-spin Fe (blue) used in planning the CDAC team’s upcoming Z-shot. To reach a second, higher-T isentrope, a pre-heated “gapless” target is being designed. [Calculations by CDAC student Hannah Bausch (NU) with former CDAC student Joshua Townsend (SNL)].

1683.  Kraus, R. G., R. J. Hemley, S. J. Ali, J. L. Belof, L. X. Benedict, J. Bernier, D. Braun, R. E. Cohen, G. W. Collins, F. Copari, M. P. Desjarlais, D. Fratanduono, S. Hamel, A. Krygier, A. Lazicki, J. McNaney, M. Millot, P. C. Myint, M. G. Newman, J. R. Rygg, D. M. Sterbentz, S. T. Stewart, L. Stixrude, D. C. Swift, C. Wehrenberg, and J. H. Eggert, Measuring the melting curve of iron at super-Earth core conditions.  Science 375, 202-205 (2022).[OSTI ID 1840054]

1685.  Perreault, C., L. Q. Huston, K. Burrage, S. C. Couper, L. Miyagi, E. K. Moss, J. S. Pigott, J. S. Smith, N. Velisavljevic, Y. Vohra, and B. T. Sturtevant, Strength of tantalum to 276 GPa determined by two x-ray diffraction techniques using diamond anvil cells. Journal of Applied Physics 131, 015905 (2022). [OSTI ID 1843424]

1693.  Dorfman, S. M., S. Najiba, B. Arroyo, S. Theuer, M. Lv and B. L. Brugman, Control of deviatoric stress in the diamond anvil cell through thermal expansion mismatch stress in thin films.  Physics and Chemistry of Minerals 49, 16 (2022). [OSTI ID 1867017]

Duwal, S., R. C. Clay III, M. D. Knudson, J. Boerner, K. Cochrane, J. Usher, D. Dolan, B. Farfan, C. de La Cruz, J. Banasek, C. T. Seagle, R. Hacking, S. Payne, C. Zoller, M. Ahart, and R. J. Hemley, Extreme compression of planetary gases: High-accuracy pressure-density measurements of hydrogen-helium mixtures above 4-fold compression. Physical Review Letters, submitted.

Clark, A.N., J.M.D. Lane, J.P. Davis, A.R. Sarafian, K.R. Cochrane, J.P. Townsend and S.D. Jacobsen. Shock-ramp of SiO2 melt. Journal of Physics Condensed Matter, in press.