Structure dependence of magnetic properties in yttrium iron garnet by metal-organic decomposition method

The yttrium iron garnet (YIG) samples are prepared at different temperatures from 900 ℃ to 1300 ℃ by the metal-organic decomposition (MOD) method. The chemical composition and crystal structure of the samples are studied by scanning electron microscope (SEM), XRD, and Mössbauer spectrometer. It is shown that the ratio of ferric ions on two types of sites, the octahedral and the tetrahedral, is increased with the sintering temperature. At 1300 ℃, the pure garnet phase has been obtained, in which the ferric ions ratio is 2:3 leading to the minimum magnetic coercivity and maximum saturation magnetization. These results provide a route to synthesize pure YIG materials as the basic materials used in various spintronics applications.