Intrinsic stacking fault energies were studied as a function of the pressure in Al obtained from first principle calculations and 2 empirical n-body potentials. Conventionally this energy was linked to the energy difference between face-centered cubic and hexagonal close-packed structure given by an approximate formula of Hirth and Lothe. The validity of this approximation at high pressures was examined and an extension was proposed which was applicable to a wide range of pressures. First-principles calculations of intrinsic stacking fault energies as a function of the pressure suggested that heavily deformed Al could partially transformed into the hexagonal close-packed phase at about 17GPa. This occurred if the density of dislocations which it contained was large.

Phase Stability and Intrinsic Stacking Faults in Aluminum under Pressure. G.S.Fanourgakis, V.Pontikis, G.Zérah: Physical Review B, 2003, 67[9], 094102 (8pp)