Effect of Nb and Cr incorporation on the structural and magnetic properties of rapidly quenched FeCoSiB microwires

Rapidly quenched microwires with a nominal composition of Fe39Co39Si8B14 (#AO), Fe37Co37Nb4Si8B14 (#AN) and Fe36Co36Nb4Cr2Si8B14 (#ANC) have been investigated. Devitrification of as-quenched microwires showed that crystallization temperatures increased with simultaneous incorporation of Nb and Cr as in #ANC alloy. Addition of these elements also contributed to an increase in activation energy in #AN and #ANC alloys. Nb addition reduced the particle size, which became much finer in the case of the Cr-containing alloy. Although Nb addition did not have much effect on lowering the Curie temperature TC of the amorphous phase, Cr substitution lowered TC to 698 K from high values of 785 K and 787 K observed in the #AO and #ANC alloys, respectively. However, the Cr addition revealed a better Giant magneto-impedance (GMI) response compared to the other alloys. Such improved GMI properties in the Cr-containing alloy are attributed to lower values of the coercivity and magnetostriction in the alloy containing both Nb and Cr.

► FeCoSiB based rapidly quenched microwires prepared by in-rotating-water quenching system.
► Effect of Nb and Cr on the thermal and GMI behavior of FeCoSiB microwires has been investigated.
► Effect of Nb and Cr on magnetic properties has also been investigated.