Effect of Ni<sub>0.5</sub>Zn<sub>0.5</sub>Fe<sub>2</sub>O<sub>4</sub> Nanoparticles Addition on Tl-1212 High Temperature Superconductor

Abstract

The effects of Ni0.5Zn0.5Fe2O4 nanoparticle addition on the superconducting and transport properties of (Tl0.85Cr0.15)Sr2CaCu2O7 (Tl-1212) superconductor were investigated in this paper. The Tl-1212 samples were produced by mixing high purity oxide powders through a solid-state reaction method. Nano Ni0.5Zn0.5Fe2O4 particles with compositions of 0.001 wt.%, 0.003 wt.%, 0.005 wt.%, 0.01 wt.% and 0.02wt.% with average size of 60 nm were added into the Tl-1212 powders. The transition temperatures (Tc-zero and Tc-onset) were measured using a four-point probe method. The highest Tc-zero recorded was 97 K which was exhibited by the pure Tl-1212 sample. The transport critical current, Ic, of the Tl-1212 samples were found through the 1 µV/cm criterion with temperature ranging from 30 K to 77 K. The sample with a composition of 0.003 wt.% displayed the highest value of Jc at 77 K with a value ranging up to 1780 mA/cm2. The Tl-1212 samples were characterised using scanning electron microscopy (SEM), powder X-ray diffraction method (XRD), energy dispersive X-Ray analysis (EDX), electrical resistance measurements and transport critical current density measurements. The Jc of the Tl-1212 superconductor has been improved through the addition of Ni0.5Zn0.5Fe2O4 nanoparticles but adding an excessive amount has caused its Jc to degrade.