Solid-state Reaction Study on Physically and Tribochemically prepared BaC2O4-SnC2O4 Mixtures

The synthesis of barium metastannate, BaSnO3, by heating mixtures of metal oxalates, either physically mixed or subjected to a phase of mechanical activation, up to temperatures in the range 750 and 1200°C has been studied. Simultaneous thermogravimetry-differential scanning calorimetry (TG-DSC) analysis and X-ray powder diffractometry (XRPD) have been applied to check the advancement of the reactions. BaSnO3, though slightly contaminated by BaCO3, can be obtained by heating the activated mixture up to T ≥ 1000 °C while heating a sample of a physical mixture at temperature as high as 1200 °C resulted in a mixture of BaSnO3, SnO2, and Ba2SnO4. Finally the heat capacity of BaSnO3 prepared at temperatures between 1000 and 1200 °C have been measured by temperature modulated differential scanning calorimetry (MTDSC) in the temperature range 50-400 °C