Magnetic performance and structural evaluation of La, Ce, Bi-substituted yttrium iron garnets

In this research work, the Ce0.15Bi0.15LaxY2.7-xFe5O12 samples (x = 0-0.2) were fabricated via the solid state route. The mixed powders were calcined at 1100 degrees C/20 h and then sintered at 1420 degrees C/6 h in the air. The structural and magnetic characteristics of the powders were examined by the X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy (RS), Scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), Transmission electron microscope (TEM), and Vibrating sample magnet- ometer (VSM). Due to the large ionic radius of the additive cations (Ce3+, Bi3+ and La3+), the dodecahedral site was the preferred substitution space for these cations. The substitution of Ce3+, Bi(3+ )and La3+ with a large ionic radius generated a microscopic deformation of the octahedral and tetrahedral sub-lattices to various degrees. This accounts for the phenomenon found in the consideration of the magnetic behavior. The XRD patterns confirmed the YIG phase. The XPS analysis indicates the small amount of Ce observed as Ce4+ in the YIG structure. The results of the magnetic analysis reveal that saturation magnetization is enhanced from 32.83 to 42.19 (emu/g) when the La content increases from x = 0 to x = 0.07 and after that it is reduced. The obtained doped garnet with high saturation magnetization and relatively low coercivity can be a potential candidate to be utilized for antenna purposes or high-frequency applications as a core material with low eddy current losses in security, switching, resonant circuits, microwave high-frequency components and magneto-optical microscopes.