Etude du premier principe des propriétés structurales, électroniques, magnétique et la pression de transition des composés Erbium Monopnictides ErX (X=N, P, As, Sb et Bi)

Abstract

In this work we have chosen a first principle calculations in the aim to study the structural, electronic and magnetic properties of rare earth types ErX (X = N, P, As, Sb and Bi). The method used was full potential augmented plane wave FPLAPW implemented in the WIEN2K code, the treatment of the exchange correlation potential was with the GGA approximation. The results prove that ErX are ferromagnetic materials and they crystallize in the NaCl structure, which is in good agreement with the available theoretical data. The calculation of the transition pressure has shown that the ErX (N, P, As and Sb) transit at high pressures from the NaCl structure to the CsCl structure while the ErBi transit at a very low pressure. In this work the ErN was found almost semi-metallic with the GGA and semi- metallic with the mBJ-GGA which is not the case for the other ErX (X = P, As, Sb and Bi) that they had a metallic character using GGA and a semi-metallic character using mBJ-GGA. We have also determined the density of state (DOS) and the magnetic moment of ErX.