Visualization of stray-field distribution by charged domain-walls in rare-earth substituted iron garnets

Magnetic-optical methods are used to investigate the magnetic microstructure of an epitaxial film of (Lu,Bi) substituted rare earth iron garnet. In particular, we focused our study on a bi-dimensional domain configuration, the Néel spike, which is induced and pinned at defects inside the sample or at its edges. Imaging of magnetic domains and domain-walls is obtained by direct magneto-optical interaction in the sample under study. The visualization of the stray-field distribution that is generated by single domain-walls is achieved by means of magneto-optical imaging with an indicator film. Furthermore, magnetostatic calculations were per- formed in order to correlate the net magnetic charge of the Néel spike domain and domain-walls with the measured stray-field. It results that the measured magnetic field intensity nearby the Néel spike tip is compatible with a Bloch-to-Néel wall transition.