title: Mechanisms for pressure-induced crystal-crystal transition, amorphization, and devitrification of SnI4.
abstract: The pressure-induced amorphization and subsequent recrystallization of SnI4 have been investigated using first principles molecular dynamics calculations together with high-pressure (119)Sn nuclear resonant inelastic x-ray scattering measurements. Above ∼8 GPa, we observe a transformation from an ambient crystalline phase to an intermediate crystal structure and a subsequent recrystallization into a cubic phase at ∼64 GPa. The crystalline-to-amorphous transition was identified on the basis of elastic compatibility criteria. The measured tin vibrational density of states shows large amplitude librations of SnI4 under ambient conditions. Although high pressure structures of SnI4 were thought to be determined by random packing of equal-sized spheres, we detected electron charge transfer in each phase. This charge transfer results in a crystal structure packing determined by larger than expected iodine atoms.
authors.affiliation: Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B2, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B2, Canada.
authors.forename: J S
authors.initials: JS
authors.lastname: Tse
authors.affiliation: Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439, USA.
authors.forename: M Y
authors.initials: MY
authors.lastname: Hu
authors.affiliation: Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439, USA.
authors.forename: W
authors.initials: W
authors.lastname: Bi
authors.affiliation: Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439, USA.
authors.forename: J
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439, USA.
authors.forename: E E
authors.initials: EE
authors.lastname: Alp
authors.affiliation: School of Physics and Astronomy, Tel Aviv University, Ramat Aviv, Israel.
authors.forename: M
authors.initials: M
authors.lastname: Pasternak
authors.affiliation: Los Alamos National Laboratory, PO Box 1663 Bikini Atoll Road, Los Alamos, New Mexico 87545, USA.
authors.forename: R D
authors.initials: RD
authors.lastname: Taylor
authors.affiliation: Los Alamos National Laboratory, PO Box 1663 Bikini Atoll Road, Los Alamos, New Mexico 87545, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Lashley