Thermodynamic Properties of Stoichiometric Non-Superconducting Phase Y₂BaCuO₅

Y₂BaCuO₅ often occurs as an accompanying phase of the well-known high-temperature superconductor YBa₂Cu₃O₇ (also known as YBCO). Y₂BaCuO₅, easily identifiable due to its characteristic green coloration, is often referred to as 'green phase' or 'Y-211'. In this contribution, Y₂BaCuO₅ phase was studied in detail with a focus on its thermal and thermodynamic properties. Energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were employed in the study of sample's morphology and chemical composition. XRD data were further analyzed and lattice parameters refined by Rietveld analysis. Simultaneous thermal analysis was employed to study thermal stability. Particle size distribution was analyzed by laser diffraction. Finally, thermodynamic properties, namely heat capacity and relative enthalpy, were measured by drop calorimetry, differential scanning calorimetry (DSC), and physical properties measurement system (PPMS). Enthalpy of formation was assessed from ab-initio DFT calculations.