Unusual magnetic properties of Au-Mn nanowires on copper and silicon substrates

The quantum properties of bimetallic supported Au–Mn nanowires on copper and silicon substrates were studied. As a result of ab initio calculations it was found that Au–Mn nanowires are antiferromagnetic in the ground state. The strong dependence of magnetic properties of supported Au–Mn nanowires on the substrate geometry and component composition was revealed. Analysis of wire geometry shows that Mn atoms are embedded into the silicon substrate. Results of our study show the strong suppressing of exchange interaction in Au–Mn nanowire on nonmetal silicon substrate in comparison to copper ones. A significant decrease was found for the energy difference ΔE between antiferromagnetic and ferromagnetic states of the supported Au–Mn nanowires in comparison to freestanding nanowires as the result of nanowire–substrate interaction.