Pinning Field Distribution and Relaxation Time of Domain Wall in 2605CO Metglas

The pinning field H_p is obtained from the discontinuous variation of permeability according to ac magnetic field amplitude. The probability distribution of pinning field P(H_p) in 2605CO Metglas ribbon of as-quenched state shows a Gaussian distribution, indicating that the pinning sites with different pinning field are randomly distributed. The permeability spectra for pinned state of domain wall are caused by the pure rotational magnetization with 1 MHz relaxation frequency. For the magnetization overcoming the pinning field, the permeability spectra are superposition of rotational magnetization and wall displacement. The average pinning field and relaxation time of wall displacement decrease with the magnetizing angle from ribbon axis, and the relaxation times are found to be exponentionally proportional to the average pinning field.