Influence of quenching rate on the structural, soft magnetic and magnetoimpedance properties of melt-spun Co69Fe7Si14B10 alloy

Melt-spun ribbons of Co₆₉Fe₇Si₁₄B₁₀ alloy have been prepared at different wheel speeds viz. 47, 34 and 17 m/s and investigated for structural and magnetic properties. Degree of amorphicity in the as-spun ribbons is found to increase with wheel speed. Amorphous phase crystallizes in two stages producing Co₂Si, Co₂B and CoSi phases on annealing. Increase in wheel speed improves soft magnetic and magnetoimpedance properties due to decrease in perpendicular anisotropy which is associated with stripe domain formation. On annealing soft magnetic properties and magnetoimpedance deteriorate due to the formation of crystalline phases.