Thermochemistry of La0.7Sr0.3Mn1−xFexO3 solid solutions (0<x<1)

The structure, the energetics and the internal redox reactions of La0.7Sr0.3FexMn1−xO3 have been studied in the complete solid solution range 0.0

Enthalpy of mixing (ΔHmix) of La0.7Sr0.3Mn1−xFexO3−γ solid solution at room temperature as a function of Fe/(Fe+Mn) ratio, x. Linear fits for the two regions at low and high x are shown as solid lines. The inset shows the content of Mn3+, Mn4+, Fe3+ and Fe4+ as a function of x based on the work by Jonker [18]. The redox reactions between different valence states of Fe and Mn dominate the energetic behavior of the solid solution.Figure optionsDownload as PowerPoint slideHighlights
► Investigated the structure, the energetics and the internal redox reactions of La0.7Sr0.3Mn1−xFexO3.
► Determined the formation and mixing enthalpy by high temperature oxide melt solution calorimetry.
► Symmetry of the perovskite, transition metal valence and energetics are interdependent.
► Thermochemical data shows convincing evidence of the interplay between the Mn4+ and the Fe4+ ions.
► Balance between different valences of Mn and Fe dominates the energetics of La0.7Sr0.3FexMn1−xO3.