Investigação
Liquid-liquid phase transition observed in selenium under dynamic compression using femtosecond X-ray diffraction at LCLS | Authors: Richard Briggs (LLNL - Lawrence Livermore National Laboratory) ; Amy Coleman (LLNL - Lawrence Livermore National Laboratory) ; Shuai Zhang (LLNL - Lawrence Livermore National Laboratory) ; David Mcgonegle (OXFORD - Department of Physics, University of Oxford) ; Federica Coppari (LLNL - Lawrence Livermore National Laboratory) ; Amalia Fernandez-panella (LLNL - Lawrence Livermore National Laboratory) ; Martin Gorman (LLNL - Lawrence Livermore National Laboratory) ; Michelle Marshall (LLNL - Lawrence Livermore National Laboratory) ; Ray Smith (LLNL - Lawrence Livermore National Laboratory) ; Orianna Ball (UOE - The University of Edinburgh) ; Stewart Mcwilliams (UOE - The University of Edinburgh) ; Vitalli Prakapenka (GSECARS - GSECARS, University of Chicago) ; Conor Krill (JHU - Earth & Planetary Scienes, John Hopkins University) ; Vinay Rastogi (JHU - Earth & Planetary Scienes, John Hopkins University) ; June Wicks (JHU - Earth & Planetary Scienes, John Hopkins University) ; Cindy Bolme (LANL - Los Alamos National Laboratory) ; Phil Heimann (SLAC - SLAC National Accelerator Laboratory) ; Eric Cunningham (SLAC - SLAC National Accelerator Laboratory) ; Hae-ja Lee (SLAC - SLAC National Accelerator Laboratory) ; Malcolm Mcmahon (UOE - The University of Edinburgh) ; Jon Eggert (LLNL - Lawrence Livermore National Laboratory) ; Dayne Fratanduono (LLNL - Lawrence Livermore National Laboratory) |
Abstract: One of the most interesting phenomena of non-crystalline materials is polyamorphism, or the ability of an amorphous material, with medium range order, to exist in several distinct modifications. In liquids, the transition between these states has been termed the liquid-liquid phase transition (LLPT) and has been observed experimentally under static compression experiments in several materials. In selenium, ab initio calculations have shown significant changes in the liquid structure with increasing pressure, yet experimental data at high-pressure is limited. Even less is known regarding the evolution of the liquid structure under rapid shock compression and whether a LLPT between complex liquid structures can occur on nanosecond timescales. Here we report on femtosecond X-ray diffraction measurements of the LLPT in selenium following shock compression and release and find that the liquid structure transformations are dramatic and we show that they can occur on nanosecond timescales. Experiments were performed at the Matter at Extreme Conditions end-station of the Linac Coherent Light Source (LCLS). This work was performed under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344. Use of the Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02- 76SF00515. The MEC instrument is supported by the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences under Contract No. SF00515. We
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