Synthesis and Investigation of Superconducting Properties of Gd and Nd doped Er123 and high entropy Er123 Cuprates

The RE123 (RE=rare earth element) compound is a common form of high-temperature superconducting (HTSC) cuprate ceramic with chemical formula REBa2Cu3O7-ᵟ. In this family, ErBa2Cu3O7-ᵟ has a critical temperature of 93 K and is known to be one of the best solders for superconducting joint fabrication. In this study, we aimed to investigate the effects of superconducting and magnetic properties of ErBa2Cu3O7-ᵟ when doped with another RE ion with a different ionic radius. Samples of Gd- and Nd-doped ErBa2Cu3O7-ᵟ superconductors are prepared systematically using the solid-state reaction (SSR) method, and the sintering parameters for phase formation are determined. The crystal structure of the Gd and Nd doped ErBa2Cu3O7-ᵟ superconductor is investigated at different doping levels using x-ray diffraction (XRD). Rietveld analysis of XRD data shows that the unit cell volume increases with Gd and Nd doping and orthorhombicity changes. Superconducting properties of these materials were investigated using DC magnetization techniques, and the effect of doping on the critical temperature (Tc), critical field (Hc), and critical current density (Jc) was studied. The relationship between the structure and superconducting properties will be discussed. We also successfully synthesized the high entropy type samples of the Er123 with 5-6 RE elements in the RE site: Y, La, Sm, Gd, Nd and Er in varying concentrations, focusing on changes in unit cell volume and average ionic radius size to observe changes in superconducting parameters: Tc, Hc and Jc.