Pressure induced zincblende to rocksalt phase transition in AlN nanocrystal

Structural phase transition in Aluminium nitride (AlN) nanocrystal has been studied within the framework of density-functional theory, using both the local-density as well as generalized gradient approximation as exchange correlation functionals. The study observes that under the application of pressure AlN nanocrystal transforms from its original zincblende (B3) type phase to hypothetical rocksalt (B1) type phase within the pressure range of 46GPa to 56GPa, which is comparatively larger than its bulk counterpart. The lattice parameter, bulk modulus and pressure derivatives of AlN nanocrystal in its original B3 type phase as well as hypothetical B1 type phase have also been computed as ground state properties. The mechanical strength of the AlN nanocrystal has been analysed in terms of volume collapse at transition pressure and bulk modulus.