Cooling rate upon in air heat treatment and magnetic properties of amorphous soft magnetic alloys

Investigation of the cooling rate effect during heat treatment in air of amorphous magnetic alloys of Fe-Ni-Si-B and Co-Fe-Ni-Cr-Mn-Si-B in states with different signs of saturation magnetostriction were performed to optimize the magnetic properties. It is shown that the increase in cooling rate from 15 to 40 °C/min contributes to the magnetic properties improvement in a state with λ_s > 0 and their deterioration in a state with λ_s < 0. This is due to the different influence of induced stresses caused by interaction of ribbon surface with atmospheric water vapor, and their value changes affected by cooling rate change.