New half-metallic ferromagnetic oxides XBe3O4 (X=Li and Na)

Abstract

The paper presents the results of the structural, electronic, magnetic, and mechanical stabilities of XBe3O4 (X = Li, Na, and K) with the space group Pm3 m, obtained by Density Functional Theory within the frame work of the Full-Potential Linearized Augmented Plane Waves method. The compounds are energetically stable in their ferromagnetic phase, while only LiBe3O4 and NaBe3O4 are mechanically stable. Both stable ones are ductile and anisotropic. The calculated spin-polarized band structures and densities of states show the half-metallic nature, with gap [half-metallic gap] of 7.73 eV [0.18 eV] and 5.57 eV [0.28 eV] for LiBe3O4 and NaBe3O4 compounds, respectively. The total magnetic moment is 1.0 μB for both systems, confirming their half-metallicity. The estimated Curie temperatures are 403.5 K and 422.9 K for LiBe3O4 and NaBe3O4 compounds, respectively. The obtained properties, such as 100% spin-polarization and high Curie temperature, required in technologies for fabricating materials for spintronic devices, make LiBe3O4 and NaBe3O4 as good candidates for these applications.