Structural properties and thermal behavior of Li2CO3-BaCO3 system by DTA, TG and XRD measurements

The binary system Li2CO3-BaCO3 was studied by means of differential thermal analysis (DTA), thermogravimetry (TG) and X-ray phase analysis. The compos ition of carbonate and CO2 partial pressure influence on the thermal behavi or of carbonate were examined. It was shown that lithium carbonate does not form the substitutional solid solution with barium carbonate, however the possible formation of diluted interstitial solid solutions is discussed. Ab ove the melting temperature the mass loss is observed on TG curves. This lo ss is the result of both decomposition of lithium carbonate and evaporation of lithium in Li2CO3-BaCO3 system. Increase of CO2 concentration in surrou nding gas atmosphere leads to slower decomposition of lithium carbonate and to increase the melting point.