The role of Dy incorporation in the magnetic behavior and structural characterization of synthetic Ce, Bi-substituted yttrium iron garnet

Abstract

In this Study, the effects of substitution of Y3+ by Dy3+ ions on the crystal structure and magnetic properties for Y2.8-xDyxCe0.10Bi0.10Fe5O12 (x = 0.0, 0.2, 0.4, 0.6) and pure yttrium iron garnet (YIG) produced by conventional method have been investigated. The Fe2O3, Y2O3, CeO2 and Dy2O3 powders were mixed in stoichiometric ratio and annealed at different temperatures from 1000 to 1420 °C in air atmosphere. At the final stage, Bi2O3 was aggraded in the YIG and annealed in 1000 °C in an air atmosphere. The phase structure, morphology and magnetic properties were investigated using Raman Spectroscopy (RS), X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscope (SEM) and Vibrating Sample Magnetometer (VSM), respectively. The X-ray diffraction data showed a nearly pure and single-phase of doped garnet with small amounts of CeO2 secondary phase. The RS result reveals the characteristic peak of the YIG structure. The XPS analysis indicates that bismuth, dysprosium, yttrium and iron ions exist in their corresponding “+3” valence states whereas cerium finds in “+3” and “+4”. The saturation magnetization augments from 33.47 emu/g for pure YIG to 35.15 emu/g for xDy = 0.2 due to the small increase in d-p wave function overlap between the octahedral Fe3+ ion and intervening oxygen ion. The coercivity values decrease from 20.16 Oe for pure YIG to 17.78 Oe for xDy = 0.6. The improved magnetic properties promote the doped garnets to microwave absorption and sensing applications.