The effect of rare earth Ce and Sm doping on the structure and magnetic properties of (Y_2.5Ce_0.5Fe₅O₁₂)_1−x/ (Mg_0.95Sm_0.05O)_x nanocomposites

Abstract Co-precipitation followed by ball-milling techniques have been used to synthesize (Y 2.5 Ce 0.5 Fe 5 O 12 ) 1−x / (Mg 0.95 Sm 0.05 O) x nanocomposites, with x = 0, 0.1, 0.2, 0.4, 0.8, and 1. Based on structural analysis, the XRD data indicated a distinct phase separation signature of Y 3 Fe 5 O 12 (YIG) and MgO, with the formation of MgFe 2 O 4 along with YFeO 3 and CeO 2 . Transmission electron microscope (TEM) showed a drastic change in particle size with a maximum value of 175 nm for YM40 nanocomposite with the increase of the concentration of Mg 0.95 Sm 0.05 O phase. Elemental analysis and surface morphology were studied using the energy dispersive x-ray (EDX) and scanning electron microscope (SEM), respectively. The purity and the crystallinity of all samples were verified with sharp peaks related to the present elements without any detected impurity elements. Fourier transform infrared showed two peaks at 916 and 864 cm −1 for Y 2.5 Ce 0.5 Fe 5 O 12 and a wide band between 415 cm −1 and 661 cm −1 for MgO, confirming the garnet structure and the stretching vibrations in MgO matrix, respectively. Strong, distinct modes were visible in the Raman spectra of YIG nanoparticles, however, two large peaks in MgO were identified as the G and D bands. X-ray photoelectron spectroscopy (XPS) was used to examine the oxidation states and elemental compositions of different elements. The M-H loops have been used to determine the magnetic properties of the samples. The saturation magnetization M s decreased from 11.23 emu g −1 to 2.68 emu g −1 as x increased from 0.0 to 0.8, caused by the weak ferromagnetism of Mg 0.95 Sm 0.05 O’s contribution to magnetization, which may also result in less super-exchange contact between the garnet’s octahedral B-sites and tetrahedral A-sites. These soft magnetization properties made the prepared nanocomposites an excellent insulator, appropriate for microwave applications like filters or sensors.