Thermal dissociation and hydrogen reduction of DyMn2O5

The dissociation and hydrogen reduction of DyMn₂O₅ have been studied in the temperature range 973–1173 K. The results were used to construct partial p-T-x phase diagrams of the Dy-Mn-O system. Our experimental data demonstrate that the thermal dissociation of DyMn₂O₅ is a three-step process, accompanied by the formation of distinct compounds in the following sequence: DyMn₂O₅ → DyMnO₃ + Mn₃O₄ + O₂ → DyMnO₃ + MnO + O₂ → Dy₂O₃ + MnO + O₂. For both DyMn₂O₅ and DyMnO₃, we have evaluated the standard enthalpy and entropy of formation from elements.