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

The influence of NiO addition on the magnetic properties of polycrystalline Y3Fe5O12 is studied for the saturation magnetization, Curie temperature, i nitial magnetic permeability and ferromagnetic resonance line width. Depend ence of saturation magnetization on NiO addition suggest that Ni2+ ions ent er octahedral sites of the: garnet lattice. Real part of the complex initia l permeability versus temperature curves reveal the single phase for sample s 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 p ermeability with NiO content are due to change of saturation magnetization and grain size of the materials. The ferromagnetic resonance line width var ies linearly with the porosity of samples with NiO showing no anisotropy co ntribution in it. (C) 2001 Elsevier Science B.V. All rights reserved.