In this work, the results of magneto-optical and magnetometric measurements carried out on YIG/FeNi film two-layer structures are presented. YIG films were grown by liquid phase epitaxy, and FeNi films were deposited using magnetron sputtering. It has been established that in the YIG/FeNi system the interlayer coupling is mainly due to the magnetostatic interaction.

Thermomagnetic processing of films of the finemet type with an easy magnetization axis in the plane under the action of a constant and rotating magnetic field was carried out in order to obtain an isotropic state. After heat treatment in a constant field, the easy magnetization axis was reoriented along the line of action of the field, as a result of which the domain walls were oriented along the new axis. After thermomagnetic treatment in a rotating field regions with different anisotropy patterns, including isotropic regions, were revealed.