Influence of magnetic fields on the critical temperature of bulk YBCO superconductor with nanometer-sized Al₂O₃ inclusions

Abstract

YBCO specimens along with different amounts of nano-sized Al₂O₃ were prepared using solid state reaction method. The structural characterization of all samples has been carried out by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The XRD patterns with Rietveld refinement procedure was used to characterize the samples crystal microstructure. SEM analysis revels the phases with distribution of Al₂O₃ nanoparticles along the YBCO grain boundaries systematically. Superconducting parameters are affected by the nanoparticle addition, and results are discussed in bearing to the structural and microstructure differences between pure Y-123 and doped Y-123. The temperature dependence of electrical resistivity ρ (T) has been measured and the effect of addition of Al₂O₃ nanoparticles with and without magnetic fields in the superconductivity and normal region has been reported.

Keywords: YBa₂Cu₃O_7-δ; Al₂O₃ nanoparticles; critical temperature; magnetic fields.