BSCCO Süper İletkeninde (Mo / W) Eş-Katkılamanın Etkileri

Abstract

The effect of Mo substituting and W doping on (BiPb) 2 W x Sr 2 Ca 3 Cu 4-y Mo y O 12+& system where x=0, y= 0; x = 0.1, y= 0.0, 0.03, 0.06, 0.09 and 0.12 have been investigated. The superconducting samples prepared by using conventional solid state reaction method. The calcination and sintering temperatures were obtained by using differential thermal analysis technique (TGA). In order to investigate crystal structure properties and determine the phase determination, X-ray powder diffraction (XRD) measurements were performed. The XRD data showed that the Bi-(2223) phase transforms into the Bi-(2212) phase with increasing Mo substituting for Cu. The morphology properties of the samples determined with the scanning electron microscopy (SEM) measurements. The effects of Mo and W substituted on BSCCO system; we have also performed electrical resistivity (R-T) in order to get critical temperatures. From electrical resistivity critical temperature and transition temperature width were both increased with the increasing of Mo content. The alternative current susceptibility measurement (AC) was performed to obtain critical transition temperature and study magnetic properties of the samples.

Superconducting Properties of Bi2-xPb0.3WxSr2Ca2Cu3O10+ Compounds

“…One can suggest that the samples had an effect on the improvement of the high-T c phase (Bi-Pb)-2223. The results disagree with those reported by Agile et al [14], Turk et al [15] and Atilla et al [16], who found that a small concentration of W negatively affected (Bi-Pb)-2223 superconductivity phase. This might be attributed to the substitution of tungsten on Ca and Cu sites in (Bi, Pb)-2223 phase, that leads to the transformation of the (Bi, Pb)-2223 phase gradually into the (Bi, Pb)-2212 phase.…”

“…However, the micrograph of x=0.4 wt % of W nanoparticles shows a different surface morphology, with grains becoming of a flower like structure, as seen in Figure-3.T. The alignment of the plate-like structures substituted with W was earlier observed [14,15].…”

“…This might be due to the increasingly weak link and (Bi, Pb)-2212 phase in this sample. The estimated T c values were increased with increasing W nanoparticles content as shown in Table-1. A number of studies [14,15,16] investigated the effects of the substitution of tungsten microparticles at Ca and Cu sites in the (Bi, Pb)-2223 phase. It was found that the superconducting transition temperature was depressed by W ion, which is the opposite of our observations.…”

“…Agil et al [14] reported the substitution of W and Mo together on (BiPb) 2 W x Sr 2 Ca 3 Cu 4-y Mo y O 12+δ system. of the results demonstrated that the substitution of (Mo/ W) in (Bi Pb) -2223 system leads to lowering T c slightly.…”