Temperature Dependence of Barkhausen Noise from Nickel

摘要

Barkhausen noise, magnetic properties and hardness were measured for heat-treated, thin plates of nickel. Uniform magnetic field was applied parallel to the surface of the plate so as to eliminate the ambiguity due to the demagnetization effect and a pickup coil was directly wound over the sample to detect Barkhausen noise only from the sample itself. The total Barkhausen noise energy was found to decrease with the increase of annealing temperature which makes the material soft. Temperature dependence of the Barkhausen noise energy was measured in a low temperature range from 4 to 300 K for the first time. The results indicate an activation-type temperature dependence which allows an estimation of the depth of pinning potential of magnetic domain wall to be 56 K.