JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS, vol.26, no.1, pp.441-447, 2015 (SCI-Expanded)
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 (q–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 Nacontents.
From the electrical resistivity measurements it
has been found that Tc is slightly higher than 92 K for Naconcentrations
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 9 106 A/cm2 at 10 K and