STRUCTURAL AND DYNAMICAL PROPERTIES OF METASTABLE AL SI SOLID-SOLUTIONS CALCULATED BY THE EMBEDDED-ATOM METHOD

Metastable fcc Al1-xSi(x) solid solutions in the low Si concentration range are modeled by the embedded-atom-method. The potential parameters for Si are fitted to the experimental lattice constant of the solutions, the cohesive energy, and the elastic properties of the metallic simple-cubic phase of Si determined by ab initio computations. The model reproduces and explains the concentration dependence of the vibrational density of states, the decrease of the shear modulus with increasing x, and allows us to simulate the first stages of the alloy decomposition into Al and Si.