Investigation on Domain Pinning Mechanism in Nanometer Hard Magnetic Materials

The domain pinning mechanism was investigated in nanometer hard magnetic materials. The pinning fields of domain wall at different inhomogeneities were studied respectively. And exchange-coupling coefficient alpha(ex) was investigated too. The results showed that alpha(ex) is proportional to the ratio of inhomogeneity thickness r(o) to wall width delta(m) for narrow inhomogeneity, while it decreases with enhancement of r(o)/delta(m) for extended inhomogeneity. At a certain value of r(o), exchange-coupling coefficient and pinning fields will reach the maximum. Exchange-coupling interaction and pinning fields are greatly influenced by inhomogeneity. Control range of inhomogeneity may obtain higher coercivity.