Number of lithium-based oxide ceramics in Li-Al-Si-O system were synthesized by solid-state reaction route using Li2CO3, Al2O3, and SiO2. The progress of the reaction was monitored using thermogravimetry. A model-free approach was employed to fit the temperature versus mass loss data. Heat capacities were measured as a function of temperature using differential scanning calorimetry. Variation of lithium/silicon ratio resulted in change in heat capacity and average crystallite size in each compound. © 2012 Akadémiai Kiadó, Budapest, Hungary.