High pressure studies on silane to 210 GPa at 300 K: optical evidence of an insulator-semiconductor transition.

Silane (SiH(4)) has been studied in a diamond anvil cell from 7-210 GPa by using optical reflection and absorption techniques at 300 K. The reflectivity and transmission measurements showed a dramatic change in the neighbourhood of 100 GPa. On the basis of reflectivity and absorption experimental data, the pressure dependence of the refractive index (n) of solid SiH(4) was derived, which was then used to determine the ratio of the molar refraction (R) to the molar volume (V).