Synthesis of Nd3+ doped nano-crystalline yttrium aluminum garnet (YAG) powders leading to transparent ceramic

Nd-doped yttrium aluminum garnet (Nd:YAG) nano-crystallites were prepared by the co-precipitation method from a mixed solution of yttrium and aluminum nitrate using ammonium hydrogen carbonate as precipitant. The phase transition and structure of the prepared powder were investigated by means of XRD and TEM. The powder showed significantly less agglomeration of crystallites, indicating a high degree of sinterability. Transparent YAG ceramics were fabricated by vacuum sintering at 1700 degrees C for 5 h using as prepared powders. The results show that an amount of added TEOS less than 0.5 wt% is suitable for the preparation of transparent ceramics. The average grain size of YAG ceramic obtained is about 2-3 mu m. The transmittance of the YAG ceramic increase as the sintering temperature and wavelength increase. The optical transmittance is about 55% in the visible range, and reaches almost 70% in the infrared. (c) 2005 Elsevier B.V. All rights reserved.