Electrical, Structural, and Thermal Properties of Ferrite/Superconductor (Ni0.5Zn0.5Fe2O4)x/YBa2Cu3O7-δ) Nanocomposite Materials

Abstract

The superconductor YBa2Cu3O7-δ (Y123) is prepared by the solid-state route, while the nanosized Ni0.5Zn0.5Fe2O4 (Ni-Zn ferrite) is synthesized via citric acid sol-gel technique. The composite material of the type (Ni0.5Zn0.5Fe2O4)x/YBa2Cu3O7-δ, where x = 0.00, 0.03, 0.10, and 0.50 wt%, is prepared by a modified solid-state method to study the effect of doping Ni-Zn nanosized ferrite on the superconducting, structure, and thermal properties of Y123. The prepared samples show Meissner effect which confirmed the presence of superconducting phase at liquid nitrogen temperature (77 K). The prepared samples have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersion of X-ray (EDX), infra-red (IR) spectroscopy, thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), DC resistance by four-probe, and critical current density measurements. It was found that by increasing Ni0.5Zn0.5Fe2O4 nanoparticles in the Y123 compound, the unit cell volume of the orthorhombic phase decreases, but the transition temperature Tc and critical current density Jc decrease for low doping (x = 0.03 wt%) then increase (x = 0.10 and 0.50 wt%) for Ni0.5Zn0.5Fe2O4 doped in Y123. The transport properties of the (Ni0.5Zn0.5Fe2O4)x/YBa2Cu3O7-δ composite as electrical resistance R, Tc, and Jc are interpreted according to Bean’s critical state model and charge-vortex interaction combined with vortex pinning in Y123 high-Tc mixed-state type-II superconductor. The critical current density Jc decreased for low doping of nanosized Ni-Zn ferrite into Y123 with ratio of 0.03 wt% and increased by increasing doping ratio to 0.50 wt%. The physical properties are improved by the coexistence of the superconductor Y123 and nanosized Ni-Zn ferrites in nanocomposite material.