Synthesis of Monodispersed Spherical Yttrium Aluminum Garnet (YAG) Powders by a Homogeneous Precipitation Method

Abstract

Monodispersed yttrium aluminum garnet (YAG) powders have been synthesized via homogeneous precipitation method from the mixed solutions of yttrium nitrate, aluminum nitrate, and ammonium aluminum sulfate using urea as the precipitant. The molar ratio of aluminum nitrate to ammonium aluminum sulfate has a significant effect on morphology and particle size of the precursor powders. It was found that spherical precursor particles can be obtained when the ratio is 1:1. During the homogeneous precipitation process, aluminum ions precipitate first and form monodispered spherical powders, and then yttrium ions precipitate onto the surface of the existing spheres. Monodispersed spherical YAG particles with 500 nm in diameter were obtained by calcining the precursor powder at 1100°C for 5 h. The so-prepared monodispersed spherical Nd:YAG powders have good sinterability, and can be sintered into transparent ceramics by vacuum sintering at 1650°C for 3.5 h.

Recent progress in advanced optical materials based on gadolinium aluminate garnet (Gd3Al5O12)

“…YAG:Ce phosphor microspheres are thus alternatively made via crystallizing the glassy microbeads quenched from melt droplets produced with laser heating [51]. Xu et al [52] identified that, with nitrate as the rare-earth source in UBHP, the aluminum source plays an essential role in the formation of precursor microspheres for YAG:Nd. They found that ammonium aluminum sulfate (alum) is indispensable and the optimal alum/Al(NO 3 ) 3 molar ratio is 1/1.…”

Application of urea precipitation method in preparation of advanced ceramic powders

“…developed this method and made it finally suitable for the preparation of fully transparent ceramics and advanced luminescent materials. Among which, work accomplished by Sun [43] etc. in 2012 should be emphasized.…”

“…FE-SEM micrographs of (a) YAG precursor during the precipitation process and (b) powders calcined at 1000 1C[43].…”

Fabrication of Yb3+-doped YAG transparent ceramics by aqueous gelcasting

“…To obtain Yb:YAG transparent ceramics with desired microstructure, its fabrication technology is very important. In recent years, many efforts have been made on YAG-based ceramics related to the synthesis of high-purity and agglomeration-free powders [8][9][10], amount and choice of sintering additives [11][12][13], optimization of sintering process [14][15][16], post-treatment [17][18][19][20], etc. Powder shaping technology was also important for obtaining highly transparent ceramics.…”