Magnetization dynamics and curie temperature study in SmCo5/Co core-shell nanostructures

SmCo₅/Co core-shell nanoparticles are studied for their ability to improve magnetic properties like coercivity and exchange-bias effects. The core-shell structure helps enhance these properties by allowing better control over the magnetic behaviour of the core, shell, and their interface. These nanoparticles can maintain strong magnetization, high coercivity, and improved energy efficiency. The structure allows for adjustable magnetic properties, giving insights into the core, shell, and their interactions effect on the overall magnetism. We use atomistic magnetic simulations with VAMPIRE software to study the magnetization reversal, coercivity, and Curie temperature in two different combination of exchange-coupled bi-magnetic hard/soft ferromagnetic core/shell nanoparticle. In the first configuration, SmCo₅ is the hard magnetic core and Co is the soft magnetic shell. The core size (d_c) varies from 0 to 4 nm, while the overall particle size stays around 5 nm. The results show that changing the shell thickness affects the microscopic interface pinning mechanism. Whether SmCo₅ is the core with Co as the shell, or vice versa, the coercivity shows little change with variations in shell thickness, but it increases significantly compared to individual Co or SmCo₅ nanoparticles. The findings confirm that the core-shell structure depends on the materials, core size, and temperature. We also investigate how the finite-size effect influences the Curie temperature of SmCo₅ and Co nanoparticles using M-T graphs. The results show that the maximum energy product (BH)_max strongly depends on core size. The SmCo₅/Co core-shell nanoparticle combination boosts magnetic performance by utilizing SmCo₅’s high magnetic strength for permanent magnets and the Co shell’s thermal stability for enhanced magnetization. This synergy makes them suitable for applications in permanent magnets, recording media, and biomedical uses.