抄録
The measurements of Barkhausen noise, magnetic properties and hardness have been performed for heat-treated, thin plates of nickel. A uniform magnetic field was applied parallel to the surface of the plate to eliminate the ambiguity due to the demagnetization effect and a pickup coil was directly wound over the sample to observe Barkhausen noise only from the sample itself. The total Barkhausen noise energy is found to decrease with annealing which makes the material soft. Temperature dependence of the Barkhausen noise energy has been measured in a low temperature range from 4 to 300 K for the first time, It shows an activation-type temperature dependence which allows an estimation of the depth of pinning potential of magnetic domain wall to be 56 K.