Effects of anisotropy on domain structures in amorphous ribbons

Using SEM techniques, magnetic domains have been studied in amorphous ribbons of Co70.3Fe4.7Si15B10annealed to produce different values of transverse anisotropy constant Ku. The average domain width varied as Ku-1/6, in agreement with theoretical models incorporating the μ-effect. Domains were also studied in ribbons annealed to produce a transition from longitudinal to transverse anisotropy. Ribbons with very low transverse Kucontain coarse and irregular domains whose widths vary with time and magnetic history. Maximum initial permeability occurs not at zero net anisotropy, but at low values of transverse anisotropy.