Resumen de DFT study of the pressure influence on the electronic and magnetic properties of Ga_(x)Mn_(1-x)N compound

Miguel J. Espitia R., Octavio José Salcedo Parra, John H. Díaz F.

• We report a firt-principles study of the pressure dependence of electronic and the magnetic properties of Ga_(x)Mn_(1-x)N compounds (x=0.25, 0.50 and 0.75) in wurtzite-derived structures. We use the full-potential linearized augmented plane wave method (FP-LAPW) within of the density functional theory framework. We found that, the lattice constant very linearly with Ga-concentration. The magnetic momento changes for a critical pressure. At x=0.75, a rather abrupt onsef of the magnetic moment from 0 to 6.02 "micro"B at P_(cr)=26.50 GPa is observed. For x=0.25 and 0.50 Ga concentrations, the magnetic moment increases gradually when the pressure decreases toward the equilibrium value. We study the transition pressure dependence to a ferromagnetic phase near the onsef of magnetic momento for each Ga_(x)Mn_(1-x)N compounds. The calculation of the density of states with Ga concentration is carried out considering two spin polarizations. The results reveal that for x=0.75 the compound behaves as a conductor for the spin-up polarization and that the density of states for spin-down polarization is zero at the Fermi level. At this concentation the compound presents a half metallic behavior; therefore this material could be potentially useful as spin injector. At high pressures P>P_(cr) the compounds exhibit a metallic behavior.