Magnetization reversal in Fe₄₈Pt₃₄B₃₄ magnetic foils

Exchange-spring magnet L1-FePt/(Fe₂B+α-Fe) is fabricated by flash annealing a melt-spun Fe₄₈Pt₃₄B₃₄ foil. A coercivity of 8500 Oe (1 Oe = 79.5775 A/m), squareness (M_r/M_s) of 0.70, saturation magnetization of 10.2 kGs (1 Gs = 10^-4 T) and an effective anisotropy K_eff =2.0 × 10⁷ ergs/cm³ are obtained. A two-step magnetization reversal feature is characterized in this paper. An exchange bias phenomenon is also observed in a low saturation field.