Thermochemical investigations of bismuth oxide doped by yttrium

The enthalpy of mixing of bismuth oxide and yttrium oxide to form Bi1.5Y0.5O3 has been determined by solution calorimetry by combining the solution enthalpies of Bi2O3, Y2O3, Bi1.5Y0.5O3 in 2 M HCl at 323.15 K. For the reaction 0.75Bi2O3(s) + 0.25Y2O3(s) = Bi1.5Y0.5O3(s), ΔoxH = −77.1 ± 2.5 kJ/mol. Bi1.5Y0.5O3 is stable with respect to decomposition to binary oxides and reaction with CO2.