Anisotropic magnetization improvement in Fe78Si9B13 glass with direct current heating

• Thermal expansion anisotropy was found in Fe78Si9B13 amorphous ribbon.
• Ms and Hc of samples change non-monotonically with increasing iDC.
• Anisotropy magnetic enhancement occurs in this alloy after DCH.
• Soft magnetic properties of Ms = 179 emu/g and Hc = 1.8 A/m was obtained by DCH.

The magnetization, electric resistivity ρ and anisotropy of Fe78Si9B13 glassy samples annealed by direct current heating (DCH) have been studied using various techniques. With increasing the direct current density (iDC), the saturation magnetization Ms and coercivity Hc of samples change non-monotonically, which can be explained by structural unit transition (fcc → bcc) at low iDC and the precipitation of Fe2B at high iDC. The samples after DCH in longitudinal direction show a higher Ms, and a lower ρ than those in transverse direction, which is due to magnetic anisotropy and thermal expansion anisotropy of Fe78Si9B13 amorphous ribbon. The sample after DCH in longitudinal direction with iDC = 2.5 × 105 A/cm2 has excellent comprehensive soft magnetic properties of Ms = 179.0 emu/g and Hc = 1.8 A/m. The anisotropic information of Fe-based glasses is helpful to fully explore the potential in their magnetic properties.