Ab initio investigations of structural, electronic and mechanical properties of aluminum nitride at standard and elevated pressures

Ab initio calculations using hybrid B3LYP functional were performed in order to investigate structural, electronic and mechanical properties of aluminum nitride as function of pressure. Electronic properties of the experimentally observed aluminum nitride modifications at standard and high pressures have been investigated. Furthermore, mechanical properties for each of the predicted and experimentally observed AlN modifications have been investigated in order to get insight into the phase stability. In addition, ductility/brittleness relationship, character of the bonding, and the relationship between calculated hardness Hv, Young's modulus E, bulk modulus B, and shear modulus K have been investigated. In this way, we address new possibilities for improving the mechanical and elastic properties of AlN based ceramic materials, as well as possible band gap tuning, which might have applications in optoelectronic devices