Magnetic Anisotropy in Thin Films of FePt Detected by the Ferromagnetic Resonance Method

Resumo

FePt thin films are made via the heat treatment of structures containing Pt (001) and Fe (001) epitaxial layers. X-ray spectral analysis and field-emission scanning electron microscopy show that the samples contain the cubic L1₂–Fe₃Pt phase and the tetragonal L1₀–FePt phase. The magnetic anisotropy of the thin films is studied by ferromagnetic resonance and magnetometric methods. The contributions from the cubic and tetragonal phases to the ferromagnetic-resonance spectrum of the sample are distinguished. The key characteristics of thin films which determine their practical applicability are determined: the Gilbert damping parameter G ~ 0.4, the first and second crystal anisotropy constants K_1⊥ = –4.08 × 10⁶ erg/cm³, K_2⊥ = 1.34 × 10⁶ erg/cm³, K_2|| = –9.76 × 10⁴ erg/cm³.