Effect of solvents on the preparation of lithium aluminate by sol–gel method Faruk Oksuzomer, S. Naci Koc, Ismail Boz * , M. Ali Gurkaynak Department of Chemical Engineering, Faculty of Engineering, Istanbul University, Avcilar, 34160 Istanbul, Turkey Received 9 August 2002; received in revised form 16 January 2003; accepted 26 October 2003 Abstract g-Lithium aluminate was prepared by sol–gel method using lithium methoxide and aluminum-sec-butoxide precursors in i-propanol, n- and tert-butanol. Clear gels could be obtained due to the addition of ethylacetoacetate and the dried solids were calcined at 550 and 900 8C. The resulting solids were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermo- gravimetric analysis/differential thermal analysis (TGA/DTA). g-Lithium aluminate with the highest purity was obtained with t-butanol solvent and LiAl 5 O 8 was the second major phase. # 2004 Elsevier Ltd. All rights reserved. Keywords: A. Oxides; B. Sol–gel chemistry; C. X-ray diffraction 1. Introduction Lithium aluminate, g-LiAlO 2 , has gained attention for its potential use as irradiation blanket for nuclear fusion reactors. It can also be used as ceramic carrier material in molten carbonate fuel cell due to its high mechanical and thermal stability [1,2]. These potential usages make the synthesis of the highest purity g-LiAlO 2 an important issue. The synthesis of pure g-LiAlO 2 by a modified sol–gel method is an alternative route to the conventional solid-state reaction [3]. Lithium aluminate has three allotropic forms and they are named a-, b-, and g-LiAlO 2 with hexagonal, monoclinic and tetragonal structures, respectively. g-LiAlO 2 is the most stable form and a-, b-LiAlO 2 phases transform to g-LiAlO 2 at elevated temperatures [3]. In the synthesis of g-LiAlO 2 , calcination above 1000 8C is considered to be ‘‘high temperature calcination’’ and below this threshold it is regarded to be ‘‘low temperature calcination’’ [9]. Preparation of lithium aluminate by the conventional solid-state fusion method, which requires the high calcination temperatures necessary for Materials Research Bulletin 39 (2004) 715–724 * Corresponding author. Tel.: þ90-212-473-70-70x17665; fax: þ90-212-591-19-97. E-mail address: ismailb@istanbul.edu.tr (I. Boz). 0025-5408/$ – see front matter # 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.materresbull.2003.10.022