Amorphous silicon formation by shearing at ultrahigh pressure

Abstract Transmission X-ray diffraction pattern taken from silicon sheared at 10 GPa revealed 8 halo rings. Their densest radii correspond to spacings of 308.4, 264.7, 187.2, 160.5, 152.8, 124.8, 104.9, and 91.5 pm, respectively. The ratios of these values correspond to those of interplanar spacings (1 1 1), (2 0 0), (2 2 0), (3 1 1), (2 2 2), (4 0 0), (3 3 1) and (4 2 0) of face-centered cubic (fcc) lattice. These facts suggest the formation of amorphous state based on fcc structure. This state remains at atmospheric pressure.