The use of thermal analysis in the study of Ca_3Al _2O_6 formation by the polymeric precursor method

摘要

Single-phase Ca_3Al_2O_6 was prepared via polymeric precursor method. The influence of the reactants nature in the Ca 3Al2O6 synthesis was investigated. For this purpose, citric acid and soluble salts of calcium (nitrate, chloride, carbonate) and aluminium (nitrate, chloride, acetate) were used as starting materials, in the presence and, respectively, in the absence of ethylene glycol. Ca 3Al2O6 resulted as single-phase after annealing at 1050 °C for 1 h only starting from calcium nitrate or carbonate and aluminium nitrate or acetate as salts precursor for Ca~(2+) and Al ~(3+) cations. The formation of Ca_3Al_2O _6 is not conditioned by the ethylene glycol presence in these mixtures. Using calcium and aluminium chlorides, the phases present at 1050 °C are Ca_(12)Al_(14)O_(33) and unreacted CaO.