Electron Momentum Density and Phase Transition in ZnS

Abstract

The electron momentum density distribution and phase transition in ZnS are reported in this paper. The calculations are performed on the basis of density functional theory (DFT) based on the linear combination of atomic orbitals (LCAO) method. To compare the theoretical Compton profile, the measurement on polycrystalline ZnS has been made using a Compton spectrometer employing 59.54 keV gamma rays. The spherically averaged theoretical Compton profile is in agreement with the measurement. On the basis of equal valence-electron-density Compton profiles, it is found that ZnS is less covalent as compared to ZnSe. The present study suggests zincblende (ZB) to rocksalt (RS) phase transition at 13.7 GPa. The calculated transition pressure is found in good agreement with the previous investigations.

Lattice Dynamic and Thermophysical Properties of AlSi (Silumine) Alloy: A DFT Study

“…The obtained energy of B2 phase is lower than B1 and B3 phases up to unit cell volume of around 250 (a.u.) 3 which predicts the structural stability of the B2 phase of AlSi [24] in comparison to B1 and B3 phases. For higher volume than this, the structural phase transition of the phase B2 to B3 is seen for AlSi.…”

High Pressure Study of Structural and Electronic Properties of PbSe

“…In order to investigate the phase transition pressure ( ) for intermediate and CsCl-type phase, we computed variation in enthalpy with pressure using GGA and LDA approximations considering certain constraint of temperature for all the three phases of PbSe compound. Since a stable phase of any crystal is coupled with its minimum free energy, we have constrained the temperature to zero in order to obtain a thermodynamically stable phase which has lowest enthalpy, H = E + PV, under given pressure [26,47]. At enthalpy of the two consecutive phases is equal [16,48].…”