way to synthesize high quality cubic yttrium iron garnet (YIG)

nanopowders. In this paper, focusing on clarifying its formation

mechanism, the thermal behaviors and the elemental distributions of the

chemical co-precipitated precursors have been analyzed by simultaneous

differential scanning calorimetry plus thermal gravimetric analysis

(DSC-TGA) and energy disperse spectroscopy (EDS) mapping technique on a

transmission electronic microscope. The results indicated that the

homogeneity of Y and Fe elemental distributions in the precursor powders

determines the process through which the cubic YIG phase would form:

one experiences the intermediate tetragonal YIG phase; the other takes

YFeO3 as the intermediate phase. The homogenous distributions

of Y and Fe elements in the precursor powders at the scale below 50?nm

forms the intermediate tetragonal YIG phase rather than YFeO3,

which leads to reduction of the formation temperature for synthesizing

the single phase YIG. The obtained YIG nanopowders with the average

particle size below 100?nm show excellent magnetic properties with

saturation magnetization of 26 emu/g and coercive field of 45?Oe. This

clear formation mechanism of YIG nanopowders is suitable for optimizing

the processing conditions for the chemical precipitation synthesis of

YIG nanopowders at large scale.