Magnetic properties of Pt–Ir nanowires

We study the magnetic properties of Pt1−xIrx nanowires by using the ab-initio wien2k code, being 0 ⩽ x ⩽ 1. It has been established in the literature that Pt and Ir nanowires show very different behaviors if spin–orbit coupling (SOC) is considered or not in the calculation of their electronic structure. Pt nanowires have magnetic order only if SOC is considered, but Ir ones show the opposite behavior. In the case of Pt1−xIrx nanowires and without considering SOC, the spin magnetic moment as a function of the Ir concentration (μ vs. x) shows an almost linear behavior between the spin magnetic moments of pure wires. While μIr is relatively high, the μPt presents very low values. On the contrary, if SOC is taken into account, a very interesting behavior is found. While the pure wires have low average magnetic moment values, being zero for Ir one and 0.15 μB for the Pt one, the curve μ vs. x shows a maximum at x = 1/2 of about 0.75 μB. We discuss the influence of equilibrium bond length and hybridization effects on the electronic properties of Pt1−xIrx nanowires.