Torsion-induced magnetoimpedance in nanocrystalline Fe-based wires

The magnetic field influence on the real and imaginary parts of axial-diagonal (ζ_zz) and off-diagonal (ζ_φz) components of the surface magnetoimpedance (MI) tensor has been studied in amorphous and nanocrystalline Fe_73.5Si_13.5B₉Cu₁Nb₃Fe73.5Si13.5B9Cu1Nb3 wires. Twisted and untwisted wires were annealed at a temperature near to that of primary crystallization. The MI response has been measured at 1 MHz and 5mArms drive current in all the samples. Even though the higher values for both components of the MI tensor are achieved for the untwisted annealed wire, the most interesting features are observed in the torsion annealed wire.