Giant magneto-impedance in nanocrystalline glass-covered microwires

Giant magneto-impedance (GMI) effect has been studied in Fe73.5Nb3Cu1Si13.5B9 glass-covered microwires after heat treatment in vacuum at different temperatures up to 600 °C for 1 h. We present studies on the frequency dependence of the GMI in the range of 1 kHz-10 MHz and the dependence of magnetostriction constant on annealing time.