Etude des propriétés structurales, Electroniques, Magnétiques et Thermodynamique des ternaires à base d’Uranium U3XSb5 avec (X= Zr, Nb et Hf) Par FP-LAPW+lo

Abstract

The aim of this work is the investigation of the structural, magnetic, electronic and thermodynamic of Antimonide Uranium U3XSb5 with (X = Zr, Hf, Nb) are crystallized in the hexagonal structure of space group (P63 / mcm) in the paramagnetic and ferromagnetic states. The calculation of these materials is carried out using the method of augmented plane wave, in total potential (FP-LAPW + lo) implemented in the program WIEN2k. When the potential exchange-correlation was treated with the approximation of the generalized gradient GGA Wu and Cohen. Furthermore, the approximation GGA + U (where U is Hubbard correlation terms) is used to treat f electrons properly. The thermodynamic properties are realized by the Debye model quasi-harmonic in which the lattice vibrations are taken into account. So our calculated on the structural parameters allowed to reproduce satisfactorily the major trends that are experimentally observed and with success. The magnetic study of these compounds indicates that these materials are ferromagnetic. In addition, we present a comparative study between the band structures, electronic structures, total and partial densities of states and local times calculated by the GGA and GGA + U approximation. Our band structure calculations show the behavior of this metal ferromagnetic compound. The relative change in volume of the heat capacities and Debye temperature with the temperature and pressure are obtained successfully.