YAG Nanopowders Research Articles

Effect of Sulfate Ions on YAG Powders Synthesized by Microwave Homogeneous Precipitation

Using A1(NO 3) 3·9H 2O, NH 4A1(SO 4) 2·12H 2O, Y(NO 3) 3 as mother salts, and urea as precipitant, YAG nano-powders were synthesized by microwave homogeneous precipitation. The composition, morphology, and phase transformation of precursor were analyzed by IR, XRD and TEM. The size distribution of YAG powders was characterized using laser diffraction method. The results show that sulfate ions influence the dispersion, composition and morphology of the YAG precursors. The addition of moderate sulfate ions can produce YAG powders with nano size and excellent dispersion at 1100 °C.

High-Pressure Induced Structural Decomposition of RE-Doped YAG Nanoceramics

The preparation of transparent nanoceramics from nanocrystalline Y3Al5O12 (YAG) powders doped with rare-earth ions has been described and the results of investigation of the structure and morphology have been presented. Decomposition of YAG nanocrystals into YAlO3 (YAP) was observed. The temperature and pressure for the decomposition was much lower than that reported for larger crystals. The transformation was connected with grain coarsening. The influence of the method of preparation of the YAG nanopowders on the final transparency of the nanoceramic produced was determined. Preliminary results of the dependence of luminescence properties on the structural transformation of the nanograins are presented.

Experiments made at the mare island navy-yard, California, with different screws applied to the united states steam launch no. 4, to ascertain their relative propelling efficiency

Yttrium aluminum garnet (YAG, Y3Al5O12)nanopowders were synthesized by a polyacrylamide gel method at a much lower temperature of 900 °C than using the traditional methods. This synthesis process was thoroughly investigated including an examination of the phase transformation, the particle size and agglomeration degree at different molar ratios of monomer to the precursor salt and the calcination temperature. A high mole ratio of monomer to the precursor salt led to low formation temperature of YAG, resulting from the high homogeneity and reduced particle size of the precursor. Consequently, weak-agglomerated YAG nanopowder with an average particle size of 35 nm can be prepared at a calcination temperature of 900 °C for 2 h. The as-prepared YAG nanopowder showed excellent sinter-ability.