Exchange-coupled FePt nanoparticle assembly

High-performance permanent magnetic materials for energy-related applications need large energy-products (BH)max. A permanent magnet with large (BH)max should exhibit both a high saturation magnetization, MS, and a large coercive field, HC. L10 ordered FePt has high MS (∼ 1100 emu/cm3) and large magnetocrystalline anisotropy constant KU (> 5×107 erg/cm3), therefore is a suitable candidate for permanent magnetic materials.