Enhancing superconducting properties of YBa2Cu3O7- ẟ through Nd2O3 addition prepared using modified thermal decomposition method

Polycrystalline YBa₂Cu₃O_7−δ (Y-123) samples with different varying weight percentages (x = 0.0, 0.1, 0.3, 0.5, 1.0, and 5.0 wt.%) of neodymium oxide (Nd₂O₃) addition have been successfully synthesized using a modified thermal decomposition method (DM) under ambient conditions. X-ray diffraction (XRD) analysis revealed favorable orthorhombicity values (~ 0.008) for the Y-123 crystal structure, and an estimated oxygen content close to the theoretical value (~ 6.8), along with the presence of light secondary phases such as Y₂BaCuO₅ (Y-211) and BaCuO₂. For FESEM analysis, it was found that 5.0 wt.% Nd₂O₃ increased porosity and reduced grain size, negatively impacting superconductivity. Conversely, 0.5 wt.% Nd₂O₃ promoted significant grain growth, leading to enhanced grain contact and a denser microstructure. Electrical resistivity measurements confirmed superconducting transitions in all samples. Notably, the 0.5 wt.% Nd₂O₃ sample exhibited an optimal T_c-onset of 94.14 K with a narrow transition width ΔT_c of 4.04 K. In contrast, the higher 5.0 wt.% Nd₂O₃ concentration resulted in a broader ΔT_c of 7.47 K, suggesting the lower doping provided more optimal superconducting performance. AC susceptibility measurements corroborated these findings. This DM method offers a cost-effective approach for Y-123 synthesis, with potential for further optimization through alkali metal doping to reduce costs and environmental impact.