Elastic properties of Si during amorphization

The behavior of shear moduli of Si have been studied during amorphization. The amorphization was achieved by irradiation with 1.8-MeV Kr ions and was monitored by means of transmission electron microscopy and Raman spectroscopy. The elastic properties were investigated using Brillouin scattering techniques. Unlike what has been observed in ${\mathrm{Nb}}_3$Ir and ${\mathrm{Zr}}_3$Al, where the elastic constant changes dramatically, even before the sample becomes amorphous, the elastic constants of Si change only when the sample shows signs of becoming amorphous.