1. Effect of the aluminum source on the formation of yttrium aluminum garnet (YAG) powder via solid state reaction Reporter : Che-Wei Kuo Adviser : Ming-Shyong Tsai Date : 2011/010/26 1

2. Yttrum aluminum garnet (YAG) are potential phosphor candidates and applications include : CCathode-ray tubes (CRT) FField–emission display (FED) VVacuum-fluorescent display (VFD) LLight-emitting diode (LED) Applications of YAG 2

3. In this research, the author try to improve the diffusion of Al 3+ in Y 2 O 3 lattice. So the author uses different aluminum sources, such as α-Al 2 O 3 、 θ-Al 2 O 3 、 γ-Al 2 O 3 and boehmite to produce YAG powders by solid state reaction method. Other methods of synthesizing YAG powders, such as : Hydrothermal synthesis method Co-precipitation method Spray pyrolysis method Sol–gel method Methods of producing YAG powders 3

4. Pure YAG powder can be formed successfully and easily by using boehmite as the aluminum source and calcining at 1500 ◦C for 5 h. The composition diffusion occurs before the phase formation of YAG. The grain growth of Y 2 O 3 and α- Al 2 O 3 are effectively suppressed in this case. The Y 2 O 3 is decomposed by the diffusion of boehmite that can be observed from the TEM morphology. Conclusions 4