Magnetoimpedance effect in Nanoperm alloys

The influence of isothermal annealing (1 h at 600 °C in Ar atmosphere) on the soft magnetic properties and magnetoimpedance (MI) effect has been studied in ribbons of the following Nanoperm alloys: Fe91Zr7B2, Fe88Zr8B4, Fe87Zr6B6Cu1 and Fe80Zr10B10. A maximum MI ratio of about 27% was measured for the nanocrystalline alloy Fe87Zr6B6Cu1 at a driving frequency of 0.2 MHz. The thermal annealing led to magnetic softening for this alloy, while a hardening is observed for the Fe80Zr10B10 alloy.