Advanced magnetic devices and storage media will rely on ultra thin ferromagnetic films; since such films are quasi two-dimensional magnets, they can have strong perpendicular magnetic anisotropy (PMA). Optimization of future materials, including improved yields, requires an ability to measure film interactions. The advanced magneto-optical indicator film (MOIF) technique is a particularly appropriate tool to obtain such information.
This technique uses a Bi-substituted yttrium iron garnet film with in-plane anisotropy, placed on top of a specimen to be analyzed. This enables the observation of the magnetic stray fields above the specimen through the magneto-optical double Faraday effect of the garnet film. This optical image of the stray magnetic fields is observed by polarized light optical microscopy. The digital difference technique is used for quantitative analysis of the magneto-optical images.
Advantages of the MOIF method:
- Real-time visualization of the magnetization dynamics.
- Any magnetic material can be investigated and only magnetic information is observed.
- Observations over a wide-temperature range
- It is simple in operation and inexpensive to construct.