Synthesis of nanocrystalline yttrium iron garnet by low temperature solid state reaction

In this work, nanocrystalline yttrium iron garnet powders were produced by low temperature solid state reaction. The phase evolution during the procedure was determined from the thermogravimetric and differential thermal analysis, and the x-ray diffraction patterns. The results of transmission electron microscopy indicated that the prepared powders exhibited grain size at the nano-level of 20 ~ 40 nm. Dense ceramics with a theoretical density of around 98% were obtained from the prepared powders after sintering at 1280 °C, a relative low sintering temperature compared with conventional ceramic processes, and the saturation magnetizations of sintered samples were also determined.

Research Highlights
► No sol or gel form during the synthesis processing using nitrates and citric acid as raw materials.
► The synthesis method needs a low heating temperature (700 oC) compared with conventional solid state reaction.
► The product is a single phase with homogeneous size distribution and nano grains (20 ~ 40 nm) confirmed by TEM.
► Dense YIG ceramic can be sintered at a low temperature (1280 °C) compared with that in conventional processing.