Controlling the sol-gel process of nano-crystalline lithium-mica glass-ceramic by its chemical composition and synthesis parameters

This paper aims to explore the impact of the parameters such as pH of the system, refluxing temperature, water quantity and chemical composition on the sol-gel synthesis of lithium-mica glass-ceramic nano-powder. The synthesis process was accomplished using two chemical composition formula (Li(1+x)Mg3AlSi3(1+x)O10+6.5xF2 and LiMg3AlSi3(1+x)O10+6xF2). X-ray diffraction, Brunauer-Emmett-Teller surface area measurement and scanning electron microscopy techniques were applied to evaluate a variety of as-synthesized samples. Consequently, a transparent homogeneous sol was obtained under the conditions as pH 4, synthesis temperature <= 50 degrees C, and mol ratio of water to chemicals <= 2. The prepared nano-powders under such conditions were in the range of 60-100 nm. The results also revealed that the mica glass-ceramics prepared based on the composition Li(1+x)Mg3AlSi3(1+x)O10+6.5xF2 possessed finer powders due to their slow hydrolysis process. Moreover, any reduction in the stoichiometric deviation of lithium mica (x) leads to acquiring finer powders. (C) 2014 Elsevier Inc. All rights reserved.