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Band gap closure, incommensurability and molecular dissociation of dense chlorine.

ABSTRACT: Diatomic elemental solids are highly compressible due to the weak interactions between molecules. However, as the density increases the intra- and intermolecular distances become comparable, leading to a range of phenomena, such as structural transformation, molecular dissociation, amorphization, and metallisation. Here we report, following the crystallization of chlorine at 1.15(30) GPa into an ordered orthorhombic structure (oC8), the existence of a mixed-molecular structure (mC8, 130(10)-241(10) GPa) and the concomitant observation of a continuous band gap closure, indicative of a transformation into a metallic molecular form around 200(10) GPa. The onset of dissociation of chlorine is identified by the observation of the incommensurate structure (i-oF4) above 200(10) GPa, before finally adopting a monatomic form (oI2) above 256(10) GPa.

SUBMITTER: Dalladay-Simpson P

PROVIDER: S-EPMC6408506 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature

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Band gap closure, incommensurability and molecular dissociation of dense chlorine.

Dalladay-Simpson Philip P Binns Jack J Peña-Alvarez Miriam M Donnelly Mary-Ellen ME Greenberg Eran E Prakapenka Vitali V Chen Xiao-Jia XJ Gregoryanz Eugene E Howie Ross T RT

Nature communications 20190308 1

Diatomic elemental solids are highly compressible due to the weak interactions between molecules. However, as the density increases the intra- and intermolecular distances become comparable, leading to a range of phenomena, such as structural transformation, molecular dissociation, amorphization, and metallisation. Here we report, following the crystallization of chlorine at 1.15(30) GPa into an ordered orthorhombic structure (oC8), the existence of a mixed-molecular structure (mC8, 130(10)-241( ...[more]

PMID: 30850606

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