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)Mg₃AlSi_3(1+x)O_10+6.5xF₂ and LiMg₃AlSi_3(1+x)O_10+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 °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)Mg₃AlSi_3(1+x)O_10+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. - Highlights: • A transparent homogeneous sol leads to prepare nanopowders in the range of 60–100 nm. • The particles synthesized at lower temperatures possess finer sizes. • The acquired product which is prepared with excessive water offers larger sizes. • Any reduction in stoichiometric deviation leads to acquiring finer powders. • Taking synthesis composition as Li_(1+x)Mg₃AlSi_3(1+x)O_10+6.5xF₂ offers finer powders