Tailoring Magnetic Properties of Fe-Based Amorphous Alloys via Ferromagnetic Element Microalloying and Longitudinal Magnetic Field Annealing

This study investigates the effects of ferromagnetic elements on the glass-forming ability (GFA) and soft magnetic properties of Fe-B-C based amorphous alloys. By combining microalloying with longitudinal magnetic field annealing (LFA) treatment, Fe-based amorphous alloys with high saturation magnetization (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B_s</i>), low coercivity (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H_c</i>), and excellent manufacturability were successfully developed. The results demonstrate that the addition of Co or Ni improves the GFA of Fe<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">86</sub>B<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sub>C<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sub> amorphous alloys, while an optimal amount of Co or a minor addition of Ni significantly enhances the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B_s</i> of the alloys. Among the investigated alloys, the Fe<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">78</sub>Co<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub>Ni<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub>B<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sub>C<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sub> alloy exhibits superior soft magnetic performance, achieving a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B_s</i> of 1.80 T and a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H_c</i> of 2.9 A/m. Additionally, the influence of LFA on the microstructure and magnetic properties was explored, with magneto-optical Kerr microscopy employed to analyze magnetic domain behavior. The results reveal that LFA modifies the magnetic domain orientation, aligning the easy magnetization axis with the ribbon direction, thus enhancing the alloy’s soft magnetic properties. These findings offer significant understanding for enhancing the properties of Fe-based amorphous alloys, which could be beneficial for their use in electronic devices.