Magnetooptic-measurement techniques for magnetic-bubble materials

Magnetic domains in thin crystal platelets of rare-earth-substituted iron garnets or rare-earth orthoferrites are readily visible when the platelets are viewed between crossed polarizers in a microscope, due to the magnetic Faraday effect. Several interesting optical-measurement techniques using this effect for investigating mobility, coercivity, wall energy, anisotropy, and imperfections are reviewed and compared.