Synthesis and Characterization of Nb Substitution on (Bi-Pb)-2223 Superconductors

• DOI: 10.1007/s10909-017-1784-0
• Publication Date: 2017-06-21T10:27:51Z
• Authors: R. Asghari; L. Colakerol Arslan; H. Sedghi; H. Naghshara
• Keywords: Transition temperature

In this study, samples of $$\hbox {Bi}_{1.65}\hbox {Pb}_{{ 0.35-x}}\hbox {Nb}_{{ x}}\hbox {Sr}_{2}\hbox {Ca}_{2}\hbox {Cu}_{3}\hbox {O}_{10+\delta }$$ were prepared by solid-state reaction method and the effect of Nb substitution for Pb on the structural and superconducting properties of this material was investigated. The room-temperature X-ray diffraction patterns indicated that all the samples have the dominant phase of high- $${T}_{\mathrm{c}}$$ (Bi-2223). However, other phases such as Bi-2212 and some impurity phases like $$\hbox {SrCu}_{2}\hbox {O}_{2}$$ , $$\hbox {CuNb}_{2}\hbox {O}_{6}$$ , $$\hbox {CaCuO}_{3}$$ and CuO were also obtained from XRD patterns. An increasing amount of $$\hbox {Nb}^{+5}$$ substitutions for $$\hbox {Pb}^{+2}$$ led to a phase transition from Bi-2223 to Bi-2212. Electrical resistivity and magnetic measurements revealed that the critical temperature and the critical current density decreases with increasing Nb content due to the enhancement of Bi-2212 phase and appearance of impurities. SEM images indicated that samples porosity changes due to the disrupted grain growth with the substitution of Pb ions with Nb ions.