Magnetic properties of R1Y2Fe5O12 derived by a sol-gel method

Fine particles of R1Y2Fe5O12 (R = Pr, Nd, and Gd) were prepared by a new salts-routed sol-gel process, and their magnetic properties were investigated by using X-ray diffraction (XRD), atomic force microscopy (AFM), vibrating sample magnetometer (VSM), and Mossbauer spectroscopy. The stock solutions were dissolved in absolute 2-Methoxyethanol (2-MOE). Heat treatments were carried out at 600-800degreesC for the thin films for I h in air, and at 800-1000degreesC for powders for 6 h in air, Nano-sized fine particles were dispersed on SiO2/Si(100). The microstructure of the films consisted of spherical grains of 500-1000 Angstrom in size and 60-150 Angstrom in surface roughness (rms). The films annealed at other temperatures exhibited almost the same trend, only differing in coercivity (H-c) and saturation magnetization (M-s) values. The largest coercivity in thin films is 64 Oe for Pr1Y2Fe5O12. The H-c increases as radius of doping ion increases from Gd to Pr. Mossbauer spectra for R1Y2Fe5O12 (R = Pr, Nd, and Gd) composed with 2 sets of 6-Lorentzians for iron.