Preparation of yttrium iron garnet nanoparticles by sol-gel method and investigation of its magnetic properties

In this work yttrium iron garnet (Y3Fe5O12 or YIG) nanoparticles have been prepared by sol-gel method, raw materials were dissolved in citric acid and warmed up and stirred to form a gel. Synthesized nanoparticles were characterized, using X-ray diffraction, Fourier transform infrared spectra and thermogravimetric and differential thermal analysis methods. Magnetic properties of the nanoparticles were measured, using vibrating sample magnetometer and Faraday balance (M-T curve). XRD patterns showed that calcining temperature is far below than that is related to the bulk sample prepared by conventional ceramic technique. From the result of vibrating sample magnetometer and Faraday balance it was found that the saturation magnetization and Curie temperature of nanoparticles are lower than those related to the bulk sample. The decrease of saturation magnetization and Curie temperature were discussed based on core-shell model and superexchange interaction, respectively.