Microstructural and magneto-optical characterization of ferrimagnetic multilayered thin-film rare-earth iron garnet heterostructures

Superlattice heterostructures consisting of alternating single crystalline ferrimagnetic yttrium-iron-garnet (YIG) and bismuth-iron-garnet (BIG) thin film layers, alternating YIG and europium-substituted BIG (EBIG), were deposited on single crystalline (111) paramagnetic gadolinium-gallium-garnet (GGG) substrates. The perpendicular magnetic anisotropy of the YIG/EBIG heterostructures makes this type of materials an extremely viable choice for magneto-optical recording. The novel properties of these layered structures can be linked to several causes such as inter-layer stresses present in the structures, diffusion of the rare-earth species at the layer interfaces, uniformity of layer stoichiometry, layer thickness ratios and layer composition.