Persistence of Covalent Bonding in Liquid Silicon Probed by Inelastic X-Ray Scattering

J. T. Okada, P. H.-L. Sit, Y. Watanabe, Y. J. Wang, B. Barbiellini, T. Ishikawa, M. Itou, Y. Sakurai, A. Bansil, R. Ishikawa, M. Hamaishi, T. Masaki, P.-F. Paradis, K. Kimura, T. Ishikawa, and S. Nanao

Phys. Rev. Lett. 108, 067402 – Published 8 February 2012

Abstract

Metallic liquid silicon at 1787 K is investigated using x-ray Compton scattering. An excellent agreement is found between the measurements and the corresponding Car-Parrinello molecular dynamics simulations. Our results show persistence of covalent bonding in liquid silicon and provide support for the occurrence of theoretically predicted liquid-liquid phase transition in supercooled liquid states. The population of covalent bond pairs in liquid silicon is estimated to be 17% via a maximally localized Wannier function analysis. Compton scattering is shown to be a sensitive probe of bonding effects in the liquid state.

Received 22 June 2011

DOI:https://doi.org/10.1103/PhysRevLett.108.067402

Authors & Affiliations

J. T. Okada¹, P. H.-L. Sit², Y. Watanabe³, Y. J. Wang⁴, B. Barbiellini⁴, T. Ishikawa¹, M. Itou⁵, Y. Sakurai⁵, A. Bansil⁴, R. Ishikawa³, M. Hamaishi³, T. Masaki⁶, P.-F. Paradis¹, K. Kimura⁷, T. Ishikawa⁸, and S. Nanao³

¹Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Tsukuba, Ibaraki 305-8505, Japan
²Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA
³Institute of Industrial Science, The University of Tokyo, Meguro, Tokyo 153-8505, Japan
⁴Department of Physics, Northeastern University, Boston, Massachusetts 02115, USA
⁵Japan Synchrotron Radiation Research Institute, SPring-8 Sayo-cho, Hyogo 679-5198, Japan
⁶Department of Materials Science and Engineering, Shibaura Institute of Technology, Toyosu, Tokyo 135-8548, Japan
⁷Department of Advanced Materials Science, The University of Tokyo, Kashiwa, Chiba 277-8561, Japan
⁸RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan