Structural phase transition and electronic properties of AlSb nanocrystal

Density functional theory (DFT) based ab-initio approach has been used to investigate the structural stability of ~1 nm sized AlSb nanocrystal in its zinc blende (B3), rocksalt (Bl) and CsCI (B2) type phases under high compression. The self consistent total energy calculations have been performed for analyzing the stability of the material and found that B3 type phase is most stable amongst the other considered phases. It is revealed that under compression, the original B3 type phase of AlSb nanocrystal transforms to B1 type phase at a pressure of about 8.9 GPa, which is larger than that of bulk crystal. The ground state properties such as lattice parameter, bulk modulus and pressure derivative have been calculated for all the three stable phases of AlSb nanocrystal. The electronic band structure analysis finds that the band gap of AlSb nanocrystal in its most stable (B3) phase is comparatively lower than its bulk counterpart.