An interatomic potential for aluminum arsenide: A molecular dynamics study

An effective interatomic potential is proposed for AlAs. Molecular dynamics technique was used to simulate the energetics of zinc-blende, wurtzite, rocksalt and NiAs crystal structures of AlAs. The calculated cohesive energy, bulk modulus and C11 elastic constant at room temperature and melting temperature agreed very well with experimental values. By constructing a common tangent to the calculated energy versus volume curves for zinc-blende and rocksalt structures of AlAs, the pressure of structural transition between these phases was found to be 10 GPa. Vibrational density of states and specific heat were compared with first-principle calculations, displaying very good agreement. The proposed interatomic potential allows us to predict the temperature dependence of several properties, such as the elastic constants and specific heat.