Low-frequency electrical noise in Ni: The effects of magnetic fluctuations

We report measurements of the low-frequency electrical noise of Ni films at temperatures from 300 K to above the Curie temperature (Tc{~}625 K). The noise magnitude is found to exhibit peaks at {~}450 K and at Tc. This behavior and the associated noise spectra are distinctly different from those of other metals in this temperature range, and we argue that they are caused by magnetic fluctuations. The form of the density of states of the responsible excitations is inferred and found to have some interesting features. {} 1996 The American Physical Society.