title: X-Ray Diffraction of Solid Tin to 1.2 TPa.
abstract: We report direct in situ measurements of the crystal structure of tin between 0.12 and 1.2 TPa, the highest stress at which a crystal structure has ever been observed. Using angle-dispersive powder x-ray diffraction, we find that dynamically compressed Sn transforms to the body-centered-cubic (bcc) structure previously identified by ambient-temperature quasistatic-compression studies and by zero-kelvin density-functional theory predictions between 0.06 and 0.16 TPa. However, we observe no evidence for the hexagonal close-packed (hcp) phase found by those studies to be stable above 0.16 TPa. Instead, our results are consistent with bcc up to 1.2 TPa. We conjecture that at high temperature bcc is stabilized relative to hcp due to differences in vibrational free energy.
authors: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.
authors: A
authors: A
authors: Lazicki
authors: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.
authors: J R
authors: JR
authors: Rygg
authors: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.
authors: F
authors: F
authors: Coppari
authors: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.
authors: R
authors: R
authors: Smith
authors: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.
authors: D
authors: D
authors: Fratanduono
authors: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.
authors: R G
authors: RG
authors: Kraus
authors: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.
authors: G W
authors: GW
authors: Collins
authors: The University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom.
authors: R
authors: R
authors: Briggs
authors: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.
authors: D G
authors: DG
authors: Braun
authors: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.
authors: D C
authors: DC
authors: Swift
authors: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA.
authors: J H
authors: JH
authors: Eggert