Decrease of the barkhausen effect and increase of the aftereffect in thin iron films at low temperatures, observed with the kerr effect

The domain wall motion in thin iron films has been studied in the temperature range from +20°C to -175°C by means of the Kerr magneto-optic effect. While at room temperature the reversal takes place by Barkhausen jumps, at -175°C the walls move nearly continuously. The distribution of the discontinuity sizes is plotted as a function of the temperature. The aftereffect increases with decreasing temperature, so that at -175°C the nuclei of the domains grow without any further increase of the field, thus, completing the reversal in a constant field. The coercivity increases with decreasing temperature.