| Preparation of Aluminum Nitride Powders and Whiskers Using Aluminum(III) Salts as a Precursor |
| Woo-Sik Jung, Seen-Ae Chae1 |
School of Chemical Engineering and Technology, College of Engineering, Yeunngnam University
1Korea Basic Science Institute Daegu Branch |
|
|
|
|
|
| ABSTRACT |
|
Aluminum nitride (AlN) powders were synthesized by using a mixture of an aluminum nitrate or sulfate salt and carbon (mole ratio of $Al^{3+}$ to carbon=L : 30). The AlN was obtained by calcining the mixture under a flow of nitrogen in the temperature range 1100-1$600^{circ}C$ and then burning out the residual carbon. The process of conversion of the salt to AlN was monitored by XRD and $^{27}$ Al magic-angle spinning (MAS) NMR spectroscopy. The salt decomposed to ${gamma}$-alumina and then converted to AlN without phase transition from ${gamma}$-to-$alpha$-alumina. $^{27}$ Al MAS NMR spectroscopy shows that the formation of AlN commenced at 110$0^{circ}C$. AlN powders obtained from the sulfate salt were superior to those from the nitrate salt in terms of homogeneity and crystallinity. A very small amount of AlN whiskers was obtained by calcining a mixture of an aluminum sulfate salt and carbon at 115$0^{circ}C$ for 40 h, and the growth of the whiskers is well explained by the particle-to-particle self-assembly mechanism. |
| Key words:
Aluminum nitride, Aluminum(III) salts, Whisker, Growth mechanism, $^{27}$ Al MAS NMR |
|
|
|
PDF Links
Full text via DOI
Download Citation 
