| Popis: |
Magnetic relaxation of the amorphous Co80−xCrxSi6B14, x=0, 2, 4, 6, 8 alloys have been investigated by the isothermal and isochronal magnetic after-effect (MAE) and the Perminvar effect. Addition of Cr influences all characteristic parameters of the MAE spectrum. It increases relaxation peak temperature Tmax, increases the width of the spectrum ΔT and suppresses relaxation intensity (Δr/r)max. Cr also significantly influences activation parameters of the magnetic relaxation. It increases the most probable activation energy Q* from 1.2 to 1.68 eV and decreases pre-exponential factor τ0 from 5×10−16 to 2×10−19 s. The increase in Tmax and Q* is probably given by the formation of strong chemical bonds between Cr and metalloids, what decreases their mobility. The stabilisation effect induced by the presence of Cr atoms can be also visible in the change of Tmax, ΔT and (Δr/r)max after annealing the samples at 573 K for 60 min. These parameters do not change in the case of the samples with higher Cr content as intensively as in the case of Co80Si6B14 sample. The stabilisation effect of Cr is also manifested by the long-time isothermal measurements as well as in the Perminvar effect measurements. Suppression of the magnetic relaxation by Cr was proven in concentration dependence of the domain wall (DW) critical field, too. It decreases with Cr content increase. |
Full Text from ScienceDirect