The effect of Al³⁺ ion substitution on microwave dielectric and magnetic properties of YIG ferrites

In this study, YIG ferrite doped with Al³⁺ ion, represented as Y₂BiFe₅-xAl_xO₁₂ (x = 0.00 to 0.10, in increments of 0.02), was synthesized using the conventional solid-state method. Samples with varying Al³⁺ ion concentrations were sintered within the same temperature range. The microstructure, dielectric properties and microwave gyromagnetic properties were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), an impedance analyzer, a vibrating sample magnetometer (VSM), and ferromagnetic resonance (FMR) linewidth. The results indicated that the Al³⁺ ion substitute into the lattice without altering the material's phase formation. At the same time, the addition of Al³⁺ ion improved the density of the material, and maintained the appropriate magnetization and ferromagnetic resonance linewidth under the premise of high dielectric constant. The results shown that at a doping concentration of x = 0.06, the samples exhibit the narrowest FMR line-width (ΔH=336.1Oe) and excellent magnetic dielectric properties (4πMs=1291.489G,ε^′=18.25@100MHz). The materials developed in this study hold promise for improving the performance of microwave devices and offer potential for reducing the size of microwave devices.