Electronic structure and half-metallicity of the new Heusler alloys PtZrTiAl,PdZrTiAl and Pt0.5Pd0.5ZrTiAl

The electronic structure and magnetic properties of the PtZrTiAl, PdZrTiAl and Pt_0.5Pd_0.5ZrTiAl Heusler alloys were investigated using the full-potential linearized augmented plane wave (FPLAPW) within the generalized gradient approximation (GGA). For the PtZrTiAl, and PdZrTiAl alloys, the results showed that these Heusler alloys were stable in the Type I structure. The (Pt, Pd)ZrTiAl Heusler alloys are found to exhibit half-metallic ferromagnetism for both the Type I and Type II structure. The total magnetic moments of the PtZrTiAl and PdZrTiAl alloys were obtained to be 3 μ_B per formula unit, which are in agreement with the Slater-Pauling rule m_tot = (Nv ? 18). The half-metalliciy characteristic exists in the relatively wide ranges of 6.06–6.78 Å, and 6.13–6.73 Å for the PtZrTiAl and PdZrTiAl alloys, respectively. To complete the fundamental characteristics of these alloys, Pt_0.5Pd_0.5ZrTiAl is predicted to be a half-metallic ferromagnet with an energy gap of 0.90 eV in the minority spin and a complete spin polarization at the Fermi level. These new Heusler alloys may become ideal candidate material for future spintronic applications.