LATTICE INSTABILITY IN ALUMINUM-SILICON SOLID-SOLUTIONS

Aluminum-silicon solid solutions have been prepared by high-pressure q uenching. Differential scanning calorimetry measurements clearly show that they are in a non-equilibrium state. Low-temperature specific hea t and inelastic neutron scattering experiments provide evidence for a large softening of the transverse acoustic phonon modes, which appears as the signature of a lattice instability. This shows that it is poss ible to heavily destabilize the fcc structure of aluminum. This sugges ts a route to investigate solid-state amorphization of a crystalline s olid solution.