Internal friction originating from random magnetism

We investigated the relation between internal friction and magnetism due to a random arrangement of magnetic atoms by using the Mn-Cu-Ni-Fe alloy, called M2052. Its internal friction and dc susceptibility were measured as a function of the temperature from 4.2 K to room temperature. As for the internal friction, two peaks were observed at around 70 K and 270 K; the peak at the lower temperature was shifted by changing the measurement frequency. A comparison of the temperature dependency of the susceptibility and the internal friction indicated that freezing of' the magnetic moments of ferromagetic clusters could cause low-temperature internal friction. We confirmed that relaxation related to the internal friction is consistent with magnetic relaxation in random magnetism.