The influence of NiO addition on the magnetic properties of polycrystalline yttrium iron garnet

Abstract The influence of NiO addition on the magnetic properties of polycrystalline Y 3 Fe 5 O 12 is studied for the saturation magnetization, Curie temperature, initial magnetic permeability and ferromagnetic resonance line width. Dependence of saturation magnetization on NiO addition suggest that Ni 2+ ions enter octahedral sites of the garnet lattice. Real part of the complex initial permeability versus temperature curves reveal the single phase for samples with NiO content. The absence of any additional peak in these curves and the invariance of Curie temperature suggest that NiO addition cannot alter the magneto-crystalline anisotropy of the material. Variations of initial permeability with NiO content are due to change of saturation magnetization and grain size of the materials. The ferromagnetic resonance line width varies linearly with the porosity of samples with NiO showing no anisotropy contribution in it.