Preparation and characterization of Co²⁺-doped LiAl₅O₈ nano-crystal powders by sol–gel technique

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• 作者：Dongying Pan ; Duorong Yuan ; Haiqing Sun ; Xiulan Duan ; Caina Luan ; Shiyi Guo ; Zhanfa Li and Lihua Wang
• 关键词：Characterization ; X-ray diffraction ; Nanomaterials
• 刊名：Materials Chemistry and Physics
• 出版年：2006
• 出版时间：10 April 2006
• 年：2006
• 卷：96
• 期：2-3
• 页码：317-320
• 全文大小：180 K

文摘

Co²⁺-doped LiAl₅O₈ (Co²⁺:LAO) nanocrystalline powder sample was obtained by sol–gel method. The gel with the composition of CoO–Li₂O–Al₂O₃ was prepared from lithium acetate, nitrates of aluminum and cobalt, citric acid, and was heat-treated at temperatures from 500 to 1000 °C. The heated powder samples at different temperatures were characterized by differential thermal and thermogravimetric analysis (DTA/TG), X-ray diffraction analysis (XRD), transmission electron microscope (TEM), infrared spectra (IR) and absorption spectra. The results show that when the gel was heat-treated at 700 °C, LiAl₅O₈ nanocrystals with size of 20–40 nm were formed. The absorption spectrum of the heat-treated powders is identical to that of tetrahedral Co²⁺ ions, which shows that Co²⁺ ions are embedded in the lattice sites of LiAl₅O₈ nanocrystals and are coordinated with four oxygens.