Improvement of superconducting properties in Na-doped BSCCO superconductor

Abstract

In this study, the effect of Na substitution on the structural, electrical and magnetic properties of Bi2Sr2Ca1−xNaxCu2O8+y superconductor with x = 0.0, 0.05, 0.075, 0.1, 0.15, and 0.2 has been investigated. The effects of partial replacement of Na for Ca have been investigated by electrical resistivity (ρ–T), scanning electron microscopy (SEM), X-ray diffraction (XRD), and magnetic characterizations. XRD results have shown that the Bi-(2212) phase is the major one independently of the Na-concentration. SEM results indicate that the microstructure of samples is improved with increasing of Na-contents. From the electrical resistivity measurements it has been found that Tc is slightly higher than 92 K for Na-concentrations up to 0.20. Moreover, this trend is maintained in the magnetic measurements where the hysteresis loops are increased with increasing Na-concentrations. The maximum calculated Jc, using Bean’s model, is around 10 × 106 A/cm2 at 10 K and ~1,000 Oe for the 0.075 Na doped samples.