Evidence of B- and Si-type magnetic relaxations in Co-based amorphous alloys

The kinetics of the structural magnetic relaxations (MRs) in the Co-based amorphous alloys has been investigated by magnetic after-effect spectroscopy. The experimental evidence and characterization of two types of MRs in the amorphous Co75B25 and Co75Si15B10 alloys are rendered in this work. The binary CoB alloy shows only the B-type MR with the most probable energy of the activation energy spectrum Q*=1.35 eV and the preexponential factor tau(0)=2x10(-17) s. In the ternary CoSiB amorphous alloy, the additional Si-type MR with Q*=1.96 eV and tau(0)=6x10(-18) s occurs. Low-temperature annealing shifts either of the relaxation parameters of both alloys to higher values. Roles of the free volumes, the dimension, and affinity of the B and Si atoms for Co in the MR are discussed.