Structural Evolution and Thermal Stability of Sr, Cu Doped CaFeO 3 Perovskite for Solid Oxide Fuel Cells Applications

Ca1-xSrxFe1-yCuyO3 perovskites (x, y = 0.1, 0.2, and 0.3) were synthesized by the conventional solid-state reaction method. XRD confirmed the retention of an orthorhombic perovskite structure, with the unit-cell volume increasing from 225.216 to 226.978 ų with dopant concentration. XRD line-profile analyses revealed composition-dependent variations in crystallite size and lattice defects. TGA showed comparatively favorable thermal stability, with CSFC2 exhibiting the lowest weight loss (1.40%). Raman spectroscopy identified minor SrCO3, CaCO3, Fe2O3, and CuO phases. The results indicate that Sr/Cu co-doping systematically modifies the structural and thermal characteristics of CaFeO3, highlighting its potential for further investigation as an IT-SOFC cathode material.