Preparation of High-Purity Ultrafine α-Al2O3 by Solid-State Reaction at Room Temperature

2008 ◽  
Vol 368-372 ◽  
pp. 683-685
Author(s):  
Cheng Wei Hao ◽  
Bo Lin Wu ◽  
Ji Yan Li

Ammonium aluminium carbonate hydroxide (AACH), with a small quantity of γ-AlOOH, was synthesized through solid-state reaction at room temperature using AlCl3·6H2O and NH4HCO3 as raw materials and polyethylene glycol (PEG-10000) as the dispersant. After calcined at 1100°C for 1.5h, α-Al2O3 powders with primary particle sizes of 20~30nm were obtained. The crystal phase, particle size and morphology of the high-purity ultrafine α-Al2O3 were characterized. The results showed that a small quantity of γ-AlOOH in the AACH decomposed and formed crystal seeds. The presence of crystal seeds reduced the nucleation activation energy and therefore reduced the phase transformation temperature.

2007 ◽  
Vol 336-338 ◽  
pp. 1327-1330 ◽  
Author(s):  
Gang Xu ◽  
Con Jiang Tu ◽  
Wen Jian Weng ◽  
Pi Yi Du ◽  
Ge Shen ◽  
...  

The synthesis of aluminum titanate solid solution (Al2(1-x)MgxTi1+xO5, x=0, 0.1, 0.2) powders was realized by solid state reaction method using fine commercial α-Al2O3, TiO2 and MgO powders as raw materials. The effect of the introduced amount of MgO on the phase formation of aluminum titanate solid solution was investigated by XRD following the phase evolution. It was revealed that the introduction of MgO strongly affects the formation of Al2(1-x)MgxTi(1+x)O5 solid solution. The easily formed MgTi2O5 acts as the nucleus prompting the formation and lowering the synthesis temperature. The microstructure and properties of the solid solution ceramics were also studied by SEM and measuring the fracture strength and the thermal expansion coefficient.


2016 ◽  
Vol 109-111 ◽  
pp. 1739-1743 ◽  
Author(s):  
Kiyoto Shin-mura ◽  
Yu Otani ◽  
Seiya Ogawa ◽  
Eiki Niwa ◽  
Takuya Hashimoto ◽  
...  

2008 ◽  
Vol 37 (11) ◽  
pp. 1881-1886 ◽  
Author(s):  
Guorong Hu ◽  
Xinrong Deng ◽  
Zhongdong Peng ◽  
Ke Du ◽  
Yanbin Cao ◽  
...  

1987 ◽  
Vol 118 ◽  
pp. 123-134 ◽  
Author(s):  
M.E. García-Clavel ◽  
M.J. Martinez-Lope ◽  
M.T. Casais-Alvarez

2021 ◽  
Author(s):  
Hang Yu ◽  
Wenwen Bu ◽  
Zijia Wang ◽  
Zhuoyue Zhao ◽  
Mehwish Jadoon ◽  
...  

Polyoxometalate nanoparticles were synthesized via a concise solid-state reaction method by directly grinding silver nitrate and the polyoxometalate (NH4)5H6PMo4V8O40 at room temperature without the assistance of a surfactant.


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