Kinetics of magnetic annealing in amorphous Fe5Co75Si4B16

The kinetics of magnetic annealing was studied through the changes of the anisotropy field in the magnetization curves of amorphous Fe
5
Co
75
Si
4
B
16
. Isothermal experiments on as-cast specimens revealed the existence of irreversible and reversible processes. The kinetic data of the reversible process were well-fitted to the expression.
\frac{H_{k} - H_{k}^{\infin}}{H_{k}^{o} - H_{k}^{\infin}} = B - m \log t
which suggests a wide distribution of relaxation times instead of a single time relaxation. The linear temperature dependence of the coefficient m is discussed based on the Vogel-Fulcher formula of relaxation time.