Crystal structure refinement and electronic properties of Si(cI16)

Aron Wosylus (1) , Helge Rosner (1) , Walter Schnelle (1) , Ulrich Schwarz (1)

1 Chemical Metals Science Department

Si(cI16) is prepared in polycrystalline form at 12(1.5) GPa at temperatures between 800(80) K and 1200(120) K. The crystal structure is refined by a full-profile method using x-ray powder diffraction data. Si(cI16) is diamagnetic (Chi0 = –5.6(1.8) x 10–6 emu mol–1) and shows a weakly temperature-dependent electrical resistivity (Rho(300 K) = 0.3 x 10–3 Ohm m). Computations of structural and electronic properties of Si(cI16) within the local density approximation evidence the metastable character of the allotrope with respect to diamond-type silicon. The calculations yield a positional parameter which is in perfect agreement with the refined value. In agreement with the experimentally observed conductivity properties, the computed density of states evidence that the Fermi level of Si(cI16) is located in a pseudo-gap.

Mots clés: Physical Sciences

Aron Wosylus, Helge Rosner, Walter Schnelle, Ulrich Schwarz. Crystal structure refinement and electronic properties of Si(cI16). Journal of Inorganic and General Chemistry / Zeitschrift für anorganische und allgemeine Chemie, 2009, 635 (4-5), pp.700. ⟨10.1002/zaac.200900051⟩. ⟨hal-00482072⟩