Fe₃Se₄ nanostructures with giant coercivity synthesized by solution chemistry

Fe₃Se₄ nanostructures have been synthesized by a one-pot high-temperature organic-solution-phase method. The size of these nanostructures can be tuned from 50 to 500 nm, and their shapes can be varied from nanosheets and nanocacti to nanoplatelets. These nanostructures exhibit hard magnetic properties, with giant coercivity values reaching 40 kOe at 10 K and 4 kOe at room temperature. The estimated magnetocrystalline anisotropy constant is 6 × 10⁶ erg cm^-3, comparable to that of hexagonal close-packed cobalt. The magnetic properties can be further tuned by substituting Fe ions by other transition-metal elements such as Co.