Emergence of Magnetic Transition in Cobalt Oxide Nanowires on Vicinal Pt Substrate

This letter is devoted to a theoretical study of the magnetic properties of supported pure and oxidized Co nanowires (NWs) on the vicinal surface of a Pt substrate. The main goal is to study the influence of oxygen on the magnetic properties of Co NWs. Transition metal atoms are magnetic, and oxygen effectively interacts with electromagnetic (EM) radiation in the optical range. Thus, by choosing the resonant frequency, it becomes possible to change the magnetic properties of oxide NW as a whole and switch the magnetic state of the wire by using an EM field. Our study has shown that Co oxide (CoO) NWs can exhibit magnetic properties in the ground state. Moreover, we observed the emergence of magnetic transition from a ferromagnetic to an antiferromagnetic state in a CoO NW under surface oxidation. We show that the magnetic properties of oxidized NWs depend strongly on the surface geometry. The study of the electronic structure of CoO NWs explains the reason for the formation of several magnetic states. The analysis of band structures of pure and oxidized Co NW shows that changes in magnetic states can be explained by the changes in band structure due to oxidation and that oxidation decreases the value of magnetic moments of the Co atoms in comparison to the pure NW. However, the values of these moments are still high.