Magnetic anisotropy and coercivity of Fe3Se4 nanostructures.

The hard magnetic properties of Fe3Se4 nanostructures were studied both experimentally and theoretically. Magnetic measurements showed that Fe3Se4 nanoparticles can exhibit giant coercivity exceeding 40 kOe at low temperature (10 K). This unusually large coercivity is attributed to the uniaxial magnetocrystalline anisotropy of the monoclinic structure of Fe3Se4 with ordered cation vacancies. The measured anisotropy constant is 1.0 × 107 erg/cm3, consistent with the result from first-principles calculations. The magnetization reversal mechanism of the nanoparticles is found to be incoherent spin rotation. [ABSTRACT FROM AUTHOR]