Abstract：The effect of before and after removal of crystal water in starting material Lu (NO₃) ₃·6 H₂ O and Al (NO₃) ₃·9 H₂ O on synthesis of Lu₃ A_l5 O₁₂ (LuAG) nanopowders by solvothermal method was investigated. As a comparison, the obtained powders were subsequently heated at 1 000 ℃ for 2 h. The phase composition, morphology and dispersion of the powders were analyzed by X-ray diffraction (XRD) , fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM) . The results show that pure phase LuAG nanopowders can be synthesized by solvothermal method using the starting materials with crystal water. The particle size is about 100 nm and has good dispersion. After heat treatment at high temperature, the structure of nanopowders tends to be complete, but has the slight agglomeration. Therefore, the removal of crystalline water in the raw materials is not conducive to the synthesis of LuAG nanopowders by solvothermal method, and the LuAG nanopowders obtained by heat treatment are well crystallized.

Keywords：Lu₃A_l5O₁₂; nanopowders; crystal water; solvothermal method; heat treatment