Preparation and characterization of Y1Ba2Cu4O8-x superconductor by CuO addition to Y1Ba2Cu3O7-x

YBa₂Cu₃O₇-x (Y123) is a superconducting material discovered in 1987 and is notable for being the first material to exhibit superconductivity above the liquid nitrogen temperature of 77 K. This material undergoes a superconducting transition at approximately 92 K and exists in both tetragonal and orthorhombic crystal structures. YBCO exhibits superconductivity in the orthorhombic phase, whereas no superconducting transition is observed in the tetragonal phase. The YBa₂Cu₄O₈ (Y124) phase is a structurally distinct superconductor closely related in composition to the Y123 phase. Unlike Y123, it contains two Cu–O chains, which make the Y124 phase more oxygen-stable. The superconducting transition temperature of this phase has been reported in the literature to be in the range of ~80–82 K. In this study, the Y124 phase was synthesized using two different methods. In the first method, a solid-state reaction was performed using stoichiometric amounts of Y₂O₃, BaCO₃, and CuO as starting materials. In the second method, pre-synthesized Y123 superconducting material was doped with a certain amount of CuO, resulting in the formation of the Y124 phase. The obtained samples were structurally and microstructurally characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Thermal behaviors and electrical properties were investigated through thermogravimetric analysis (TGA) and temperature-dependent resistivity (R–T) measurements, respectively. Magnetic properties were examined using magnetization–temperature (M–T) and magnetization–magnetic field (M–H) measurements.