Influence of hydrogen on the magnetic properties of amorphous Fe---Si---B fibres

The saturation magnetization and switching characteristics of amorphous Fe77.5Si7.5B15 fibres were investigated after hydrogen incorporating by the electrochemical method. The switching field (H*) increased from its as-received value (5.57 Am−1 to 18.62 Am−1 after charging with a current density (Ich) of 30 mA cm−2 for 2 h. The saturation magnetization (Ms) decreased with hydrogen content up to a critical concentration corresponding to Ich = 60 mA cm−2 after 2 h of charging. At this critical current density, Ms decreased from 1.57 T, its as-received value, to 0.89 T. The results are explained by considering various kinds of interaction of hydrogen with metals, such as electron exchange, volume dilation, etc.