Elastic properties of a metallic glass relative to the crystal

The elastic properties of a metallic glass have been calculated in a tight-binding model for the attractive part of the energy and a Born-Mayer-type potential for the repulsive one, and have been compared to those of the crystalline phase. The bulk modulus at 0 K is shown to be similar in both phases, but decreases more rapidly with temperature in the glassy state. The Debye frequency is reduced by a factor of 10 to 20% in the glassy state due to the disorder, i.e., the occurrence of soft modes. This also induces a large decrease in the shear modulus. Both effects are in agreement with the existing experimental results.