The high pressure behaviour of InSb and β-SiC

Abstract

On the basis of the Gaussian-nonlocal pseudopotential scheme, modifications on the structural and electronic properties of direct band gap semiconductor InSb and an indirect band-gap semiconductor β-SiC in respect to the variation of the lattice constant are discussed. The results of valence and conduction band edge charge densities of this material for the zinc blende phase as a function of atomic volume up to 70% are used to analyze the bonding properties in these semiconductors. Trends in bonding are used to predict the pressure induced structural phase transitions in InSb and β-SiC from the zinc blende structure ( N c = 4) to the insulating rocksalt structure of NaCl ( N c = 6) or into a white-Sn like structure ( N c = 6). Analysis of the valence band edge charge densities as a function of volume shows that β-SiC transforms at high pressure to the β-Sn phase which is free-electron like metal while InSb undergoes a series of structural phase transitions with pressure.