High-pressure behavior of alpha-boron studied on single crystals by X-ray diffraction, Raman and IR spectroscopy

Irina Chuvashova , Elena Bykova , Maxim Bykov , Volodymyr Svitlyk , Biliana Gasharova , Yves-Laurent Mathis , Razvan Caracas (1) , Leonid Dubrovinsky , Natalia Dubrovinskaia

1 LGL-TPE - Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement

In the present study single crystals of rhombohedral alpha-B were investigated under pressure to 60 GPa by means of single-crystal X-ray diffraction. The bulk modulus of alpha-B was found to be K=224(7) GPa (K'=3.0(3)). Measurements of interatomic distances as a function of pressure revealed that the intericosahedral two-center two-electron (2c-2e) bonds are almost as stiff as some of intraicosahedral ones. The three-center two-electron (3c-2e) intericosahedral bonds show much higher compliance compared to other bonds in alpha-B. The vibrational properties of alpha-B under pressure were investigated by Raman spectroscopy at pressures up to 160 GPa and IR spectroscopy at pressures up to 53 GPa.

Mots clés: Alpha-boron; High pressure; IR spectroscopy; Raman spectroscopy; Single crystal

Domaines: Planète et Univers [physics]

Irina Chuvashova, Elena Bykova, Maxim Bykov, Volodymyr Svitlyk, Biliana Gasharova, et al.. High-pressure behavior of alpha-boron studied on single crystals by X-ray diffraction, Raman and IR spectroscopy. Journal of Solid State Chemistry, 2017, 245, pp.50-60. ⟨10.1016/j.jssc.2016.10.002⟩. ⟨hal-02329287⟩