Specific heat and enthalpy of crystallization CaCu3+ xTi4O12+ xin TGA and DSC isothermal oxidation at 1000 °c

Abstract

Investigation of CCTO perovskite ceramics is widely examined due to having a huge dielectric constant and can be promising for various electronic applications. This paper studied the thermodynamic and decomposition of CCTO precursors by using an isothermal simultaneous TGA/DSC experiment at 1000 °C using oxygen gases. The isothermal treatment for crystallization of CaCu3+xTi4O12+x chemical formula excess of Cu oxide by x = 0.0, 0.02, 0.08, and 0.1 batches can detect their specific heat capacity and enthalpy of fusion and crystallization. This information is useful for manufacturing quality assurance determination. The Cp different from the optimum point of crystallization and fusion is decreased with higher x values, the sample prepared with stoichiometry ratio x = 0.0 is 13.06 J/g °C. While the smaller Cp different for x = 0.1 with 9.97 J/g °C. The calculated enthalpy of crystallization is higher for sample 0.0 with ΔHCry = 238.16 J/g and the lowest is for x = 0.1 with 142.50 J/g. The XRD patterns of oxidized samples indicate the formation of perovskite CCTO structure with lower peaks intensity of lattice parameters due to present more Cu cation in the system.