Etude des propriétés électroniques des composés LiAlSi et LiAlGe

Abstract

In this work, we carried out a study on the half-Heusler compound LiAlSi and LiAlGe in order to determine its structural and electronic properties and this using the FP-LAPW (Full Potential Augmented Linearized Plan Wave) method, based on the density functional theory (DFT) and implemented in the WIEN2k code. We estimated the exchange-correlation potential by the local density approximation (LDA) and the generalized gradient approxima- tion (GGA-PBE). The TB-mBJ approximation is used to predict the elec- tronic properties. The structural properties reveal that the calculated lattice constants agree well with the experimental values. On the other hand, the bulk modulus (B) and its derivative are determined. The calculation of the electronic properties reveals that the LiAlSi et LiAlGe compounds in the phases α and β are a semiconductors and the γ phases are metallic.