UFAS1 PLATFORM EVENTS, International Conference on Materials Science ICMS2018

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Structural, Elastic and Electronic properties of the AlX (X = N, P and As) in the B3 and B1 phases
BEDJAOUI Abdelhak

Last modified: 2018-08-01

Abstract


The structural, elastic and electronic properties under pressure effect of the AlX (X = N, P and As) compounds in the ZnS-type (B3) and NaCl-type (B1) structures were investigated using first-principles pseudopotential plane wave method based on density functional theory (DFT) with the LDA and GGA as implemented in the CASTEP code. Our results confirm that these compounds crystallize in the zinc-blende phase (B3) at ambient conditions and undergo a structural phase transition from the B3 phase to B1 phase under the effect of hydrostatic pressure. Computed single elastic constants increase linearly with increasing pressure and verify the generalized stability criteria. It is found that the hardness of the AlX (X = N, P and As) compounds decreases with increasing atomic number Z of the X element. Calculated electronic properties reveal that the three considered compounds in the B3 phase and the AlN compound in the B1 phase are indirect band gap ( ) semiconductors, while the AlP and AlAs compounds in the B1 phase are metals. The nature of the fundamental band gap remainders unchanged under pressure effect. Calculated density of states reveals that these compounds possess a mixture of ionic and covalent bonding.