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  • Küçük Resim Yok
    Öğe
    Effect of Vanadium-Titanium Co-doping on the BPSCCO Superconductor
    (Springer, 2011) Yazici, Duygu; Ozcelik, Bekir; Altin, Serdar; Yakinci, M. Eyyuphan
    We have produced the (BiPb)(2)V (x) Sr2Ca3Cu4-y Ti (y) O12+delta compounds for x=0.05 and y=0, 0.05, 0.10 and 0.20 by glass-ceramic method. The effects of vanadium adding and Ti doping on the structure have been investigated by electrical resistance, scanning electron micrographs (SEM), XRD patterns and magnetic hysteresis loop measurements. It has been found that the high-T (c) superconducting phase, (2223), is formed in the samples annealed at 845 degrees C for 185, with concentration x=y=0.05. However, with increasing Ti doping the (2223) phase transforms into the (2212) phase. We have observed no superconducting properties for x=0.05 and y=0.20 compound. It has completely transformed to semiconductor. In addition, the critical current densities (J (c)), calculated from the hysteresis loop measurements by using Bean's critical state model are obtained for the samples in the same doping range. Our data have indicated that J (c) decreases with increasing temperature and Ti concentration.
  • Küçük Resim Yok
    Öğe
    Improvement of High Tc Phase Formation in BPSCCO Superconductor by Adding Vanadium and Substituting Titanium
    (Springer/Plenum Publishers, 2011) Yazici, Duygu; Ozcelik, Bekir; Yakinci, M. Eyyuphan
    We have produced the (BiPb)(2)V (x) Sr2Ca3Cu4-y Ti (y) O12+delta with x=0.1 and y=0.050,0.10,0.2 and 0.3 compounds by melt-quenching method. Structural and superconducting properties of the produced samples were investigated by Scanning Electron Microscopy, X-ray diffraction patterns, electrical resistance measurements and dc-magnetic hysteresis loop measurements. The pure high-T (c) phase (2223) is nearly found with Ti substitution for x=0.05 and 0.10. The onset critical temperature (T (c).(onset)) of the samples increases up to 111 K with doping up to x=0.20. In addition, considerable large values of the critical current densities (J (c)), calculated from the hysteresis loop measurements by using Bean's critical state model are obtained for the samples in the same doping range. Our data have indicated that J (c) decreases with increasing temperature and Ti concentration.