Influence of hydrogen charging on magnetic and magnetoimpedance properties of FeSiB and CoFeSiB amorphous wires

The magnetic and magnetoimpedance (MI) effect properties of amorphous ferromagnetic Fe77.5Si7.5B15 and (Co0.94Fe0.06)72.5Si12.5B15 were studied before and after hydrogen charging by an electrochemical method. The hydrogen charging was carried out at 25 °C and in a stirred solution by applying a constant current density of 20 mA/cm2 for 1 h. It was found that the saturation magnetization of FeSiB wire decreased from 1.6 to 1.345 T and the magnitude of the MI effect decreased from 24.4 to 7.1 after hydrogen charging. No remarkable variation in the shape of the magnetization loop and the MI effect in CoFeSiB wire were observed after hydrogenation.