Substrate-Controlled Magnetism: Fe nanowires on vicinal Cu surfaces

Abstract

Here we present a novel approach to control magnetic interactions in atomic-scale nanowires. Our ab initio calculations demonstrate the possibility to tune magnetic properties of Fe nanowires formed on vicinal Cu surfaces. Both intrawire and interwire magnetic exchange parameters are extracted from DFT calculations. This study suggests that the effective interwire magnetic exchange parameters exhibit Ruderman--Kittel--Kasuya--Yosida-like (RKKY) oscillations as a function of Fe interwire separation. The choice of vicinal Cu surface offers possibilities for controlling the magnetic coupling. Furthermore, an anisotropic Heisenberg model was used in Monte Carlo simulations to examine the stability of these magnetic configurations at finite temperature. The predicted critical temperatures of the Fe nanowires on Cu(422) and Cu(533) surfaces are well-above room temperature.