X-Ray Diffraction of Platinum at High Pressures

Laser-driven experiments at the University of Rochester's Laboratory for Laser Energetics were performed to test theoretical predictions of a solid--solid phase transformation in platinum at high pressures and temperatures.\footnote{ L. Burakovsky\textit{ et al.}, J. Phys.: Conf. Ser. \textbf{500}, 162001 (2014).} Platinum is of interest because it is often used as a calibration standard in high-pressure experiments. Powder x-ray diffraction\footnote{ J. R. Rygg \textit{et al.}, Rev. Sci. Instrum. \textbf{83}, 113904 (2012).} was used to measure the crystal structure of platinum shocked, then ramp compressed to pressures up to 300 GPa. These experiments serve as additional measurements of shock-ramped, shocked, and shock-released platinum completed at Sandia National Laboratories and the National Ignition Facility. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0003856, the University of Rochester, and the New York State Energy Research and Development Authority.