Magnetic Dynamics and All-Optical Switching in 5 nm Dy–Fe Nanostructures

Dysprosium (Dy) is ranked among those rare earths which have relatively high magnetic moment and behaves as a ferromagnetic well below room temperature (RT) with low Curie temperature. RT ferromagnetism in Dy-based alloys presents itself as a highly efficient candidate for thermally induced magnetic switching applications. A minute content of Fe in specifically designed nanostructure could introduce RT magnetization in Dy-based alloyed nanostructure. In this context, here, we present underlying magnetic dynamics and laser-induced magnetic switching in the novel design of Dy–Fe nanostructures by atomic spin model simulations. Monte Carlo and Landau–Lifshitz–Gilbert–Heun simulation integrators in addition to a femtosecond pulsed laser for an abrupt thermal pulse applied to explore the unprecedented magnetic behavior of random alloy, bilayer, and core–shell novel nanostructural designs of 5 nm sizes with 5 at % Fe contents in Dy. The practicability of these nanostructures having various sizes and designs for ultrafast magnetic switching in magnetic recording media is demonstrated.