Kerr rotation spectra of Bi‐substituted polycrystalline YCaVIn iron garnets

The Kerr rotation spectra of polycrystalline garnets BixY2−xCa1.0V0.5In0.7Fe3.8O12 (x=0–1.6) were measured in the range 1.8–3.4 eV to study the effect on Bi on the magneto‐optical effect of polycrystalline YCaVIn garnets with a narrow linewidth of ferromagnetic resonance at 9 GHz (ΔH=1.6 Oe). Negative peaks appear on the Kerr rotation spectra of the samples containing Bi. The absolute value of the peak increases with the concentration of Bi, while the saturation magnetization at room temperature does not vary much and the Curie temperature increases. The Kerr rotation of the sample without Bi is much smaller, with its spectrum similar to that of yttrium iron garnet as reported in the literature. The reflectivity spectra for all samples are similar, showing a transition at about 2.8 eV, but the transition frequency shifts with Bi incorporation.