Magnetic anisotropy and magnetic moments distribution in Fe_3O_4 magnetic films irradiated by swift heavy ions: Theoretical modelization and experimental results

摘要

The static and dynamic magnetic properties of the polycrystalline Fe_3O_4 films, are sensitive to 2.03 GeV Kr ions irradiation and exhibit diverse behaviors with different fluence. According to the static and dynamic magnetic measurement results, demagnetization energy (E_d) and effective magnetic anisotropy (E_(eff)) of the irradiated films are estimated. In addition, a phenomenological model, which is dominated by irradiation damage and stress (magnetoelastic energy, E_λ), is presented in order to fit and explain experimental data. The micro-model of the damage in films is.reasonable and can better accord with the experimental data, which indicate that the magnetic anisotropy can be modified by SHI irradiation and the distribution of the magnetic moments in films is dominated not only by E_d but also by E_λ.