Preparation of micrometer-sized α-Al2O3 platelets by thermal decomposition of AACH

✍ Scribed by Wei-Li Wang; Jian-Qiang Bi; Yong-Qiu Qi; Zheng Zhang; Zheng Xing; Hui-Ling Zhu; Dong Guo; Jiu-Jiao Xu; Yu-Jun Bai

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 497 KB
• Volume: 201
• Category: Article
• ISSN: 0032-5910
• DOI: 10.1016/j.powtec.2010.04.010

✦ Synopsis

Micrometer-sized α-Al 2 O 3 platelets with hexagonal shape were prepared by thermal decomposition of ammonium aluminum carbonate hydroxide (AACH) using AlF 3 as an additive. The precursor and the calcined product were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy and differential scanning calorimetry. The α-Al 2 O 3 platelets with the size of 2-3 μm were obtained by calcining AACH at 1200 °C with 5 wt.% AlF 3 . The morphology modification is attributed to the various growth rates along different crystal orientations due to the adsorption and uneven distribution of AlF 3 . A step growth mode is responsible for the formation of the platelets.