Analysis of Phase Diagram of CaO-CoOx-ErOy and Crystal Structure of Perovskite (Ca3−xErx)Co2O6−z Solid Solution

In this work, a series of compounds in the CaO-CoOx-ErOy ternary oxide system were synthesized air at 885 °C, using high temperature solid-phase synthesis method. The phase boundary each solid solution region was determined by X-ray powder diffraction techniques. diagram °C includes three solutions: (Ca3−xErx)Co4O9−z (0 ≤ x 0.9), (Ca3−xErx)Co2O6−z 1.25), and (Er1−xCax)CoO3−z 0.33). Four three-phase regions five tie-line obtained. structure perovskite has been analyzed Rietveld refinements. With increase Er content, cell parameters exhibit decreasing trend b directions an increasing c direction. A brief comparison diagrams CaO-CoOx-ROy (R = La, Dy, Er) systems is provided.