Synthesis and structural analysis of FeSe superconducting material prepared via sol-gel method

Calcium-partially substituted FeSe superconducting materials were successfully synthesized using a one-step sol–gel approach. Structural analysis confirmed the formation of the β-FeSe phase as the dominant structure, along with the emergence of secondary phases at higher dopant concentrations. The tetragonal lattice parameters were calculated to be in the ranges of 3.465–3.786 Å (a) and 5.518–5.869 Å (c). FTIR analysis further verified the formation of the targeted structure, with characteristic absorption peaks observed in the 390–500 cm -1 range. UV–Vis spectroscopy revealed a general decrease in absorption intensity with increasing Ca 2+ substitution. FESEM morphological analysis indicated a reduction in grain size as the dopant concentration increased.