Complex permeability after-effects in an annealed Co-based amorphous alloy

We have investigated the magnetic after-effects (MAEs) of the real and imaginary parts of the ac inverse permeability r [ r (t) ≡ 1/ μ = r 1 (t) + j r 2 (t) ]. For a near-zero magnetostrictive CoFeCrSiB amorphous alloy, it was found that r 1 ( t ) after demagnetization increases, whereas r 2 ( t ) mostly decreases. The activation energy spectra which control the MAE 1 and MAE 2 of r 1 ( t ) and r 2 ( t ), respectively, show different distributions p 1 ( Q ) and p 2 ( Q ) in the range 0.72–1.1 eV, with maxima at 0.78 eV ( τ 0 = 3.6 × 10 −14 s).