A SIMPLE MODEL FOR ELASTIC CONSTANTS OF TRANSITIONAL METALLIC GLASSES

Abstract
The elastic constants of amorphous transition metals have been explained in a semiquantitative way within a tight binding model for the attractive part of the energy and a Born Mayer type potential for the repulsive one. This is a model already used with success to describe the elastic constants of crystalline transition metals. The bulk modulus at zero temperature is shown to be similar in the crystalline and the glassy states. The shear modulus and the Debye temperature are shown to be lowered in the glassy state due to the random directions of vibrations of the different atoms. This effect is handled through a calculation of the Einstein frequency of an atom which will vibrate in the direction whose Einstein frequency is minimum. These directions of easiest vibrations are related to the structural description of the glassy state and ensure the occurrence of soft modes.