Magneto-optical properties of a sputtered Bi-substituted Dy–Fe garnet-ferrite/hematite bilayer

Rapid thermal annealing was performed after a Bismuth-substituted Dy iron garnet-ferrite (Bi2DyFe4GaO12) was deposited on a quartz glass substrate having a hematite underlayer, and the effect of the hematite underlayer on the magneto-optical characteristics of the garnet ferrite film was evaluated. The presence of the underlayer greatly improved the magneto-optical effect of the garnet film, but the amount of improvement depended on the hematite phase. Big improvement was obtained using underlayer phases that are easily crystallized, i.e., Fe3O4 and γ-Fe2O3 which have a spinel structure, but not with α-Fe2O3 which has a corundum structure.