The influence of reversible adsorption of water molecules on the domain wall dynamics in amorphous ferromagnets

The influence of weakly adsorbed molecules on the 180° domain wall (DW) dynamics in the near-surface region of amorphous ferromagnets of composition Fe76.5Cu1Nb3Si13.5B6 is observed by the magnetooptical method at room temperature. The high deceleration of an oscillating DW in the near-surface region and the decrease of the relaxation frequency from 10 to 4 kHz is observed for the pressure of water vapour in the range of 400–1300 Pa. The effect is explained by the influence of surface magnetic defects, caused by pressure on the micropore’s walls located on the surface of ferromagnets. The pressure is induced by H-bond adsorbed clusters of water molecules.