Magnetic Properties of R-YIG (R = La, Nd, and Gd) Derived by a Sol-gel Method

Y3-xRxFe5O12 (R = La, Nd, and Gd) powder were fabricated using a sol-gel pyrolysis method. Their magnetic properties and crystalline structures were investigated using x-ray diffraction (XRD), a vibrating sample magnetometer (VSM), and Mossbauer Spectrometer. The Mossbauer spectra for the powders were taken at various temperatures ranging from 12 K to Curie temperature (Tc). The isomer shifts indicated that the valence states of Fe ions for the 16(a) and 24(d) sites have a ferric character. The saturation magnetization (Ms) increases from 32 to 34 (emu/g) for the YIC, and Nd-YIG, respectively. However, Ms decreases to 27 (emu/g) at Gd-YIG.