Comparative study of electrical transport and magnetic measurements of Y₃Ba₅Cu₈O_18±δ and YBa₂Cu₃O_7−δ compounds: intragranular and intergranular superconducting properties

We compare the superconducting properties and flux pinning characteristics between YBa₂Cu₃O_7−δ (called Y-123) and Y₃Ba₅Cu₈O_18±δ (called Y-358) compounds. Both samples were synthesized through the solid-state reaction. The samples were examined by X-ray diffraction, and scanning electron microscope coupled with energy dispersive spectrometry. The critical current densities of the prepared samples were investigated using current–voltage, magnetization measurements and ac-susceptibility. It is demonstrated that the Y-358 exhibits better superconducting and pinning properties than the Y-123 one. This may be ascribed to the layered structure and the occurrence of a greater number of insulating layers between the CuO₂ planes that act as effective pinning sites and consequently conduce to a better fundamental pinning capacity in Y-358.