Influence of substitution of transition elements for boron on the induced magnetic anisotropy in cobalt base amorphous alloys

The effect of substitution of a few percent of V, Nb for boron in cobalt base amorphous alloys on the magnetic anisotropy has been investigated. The kinetic curves of the formation of induced magnetic anisotropy have been measured with a sensitive torque magnetometer and the kinetic parameters have been calculated by assuming that the distribution of relaxation times obeys a lognormal law. These results show that the substitution of V or Nb for boron in Co-based amorphous alloys can reduce the saturation value of the induced magnetic anisotropy Ku^{\infin}(T) effectively but have only a slight effect on the kinetic parameters. The relationship between the substitution of transition elements, the reduction of Ku(T), the improving of the soft magnetic properties and its stabilization has been discussed.