Static and dynamic behaviour of complex domain walls

It was previously shown that the application of high-amplitude high-frequency drive fields to epitaxial garnet films affects the properties of the walls to give increased hysteresis, and peculiar modes of oscillation in low frequency test fields. Microscopic observations can also be made to show the behaviour of the walls in the high frequency fields themselves for direct correlation with measurements of magnetization amplitude and phase versus drive field amplitude. A rapidly progressive and irregular pinning of the walls is observed in a critical field region. The low frequency observations do not indicate corresponding high frequency modes of oscillation but are relevant to the interpretation of the results in terms of cumulative Bloch line formation.