Abstract

BAEZ CRUZ, Ricardo E.; DIAZ F, Jhon H.  and  ESPITIA R, Miguel J.. VARIATION OF MAGNETISM OF Cr1-XGaXN DUE TO THE PRESSURE: A DFT STUDY. Rev. LatinAm. Metal. Mater. [online]. 2014, vol.34, n.1, pp.142-147. ISSN 0255-6952.

We report a firt-principles study of the pressure dependence of electronic and the magnetic properties of Cr1−xGaxN 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 vary linearly with Ga-concentration. The magnetic moment changes for a critical pressure. At x = 0,75, a rather abrupt onset of the magnetic moment from 0 to 2,2 µB at Pcr = 22,65 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 onset of magnetic moment for each Cr1−xGaxN 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 concentration the compound presents a half metallic behavior; therefore this material could be potentially useful as spin injector. At high pressures P > Pcr the compounds exhibit a metallic behavior.

Keywords : FP-LAPW; Magnetic semiconductors; Pressure dependence..

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