Journal ArticleDOI
Superconductivity in the Bi - Sr/K - Ca/Na - Cu - O system
TLDR
In this article, the role of double doping at the Ca and Sr sites simultaneously in the Bi-2212 composition was studied and it was found that the structure is single-phase Bi-2012.Abstract:
Samples with the stoichiometric composition with x = 0.1 and y = 0.1, 0.2, 0.3 and 0.4 were prepared by the solid state reaction method. The role of Na and K doped at the Ca and Sr sites simultaneously in the Bi-2212 composition was studied. From the x-ray diffraction data it was found that the structure is single-phase Bi-2212. From the resistivity data the varies from 63 to 67 K for different dopant levels. The diamagnetic nature of the samples was confirmed by ac susceptibility measurements. The oxygen content was determined by the two-step iodometric titration technique. The present results on the effect of double doping are compared with those of single dopants published earlier by our group. The microstructures of the samples were examined by scanning electron microscopy.read more
Citations
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Thermoelectric power in Bi2Sr2−xKxCaCu2Oy
TL;DR: In this paper, the superconducting and normal state transport properties of ceramic samples with composition Bi 2 Sr 2−x K x CaCu 2 O y ( x ǫ = 0, 0.1, 0., 0.2, 0, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) have been investigated by measuring thermoelectric power.
Journal ArticleDOI
Improvement in high-Tc phase formation in (thallium–antimony) doped bismuth-based superconducting materials
TL;DR: In this article, a combination of Tl 0.3−x Sb x is found to promote the formation of high-Tc (Bi-2223) superconducting phase in Bi 1.7 Pb 0.4 Sr 2 Ca 2 Cu 3 O y compound which consequently results in enhancement of the critical temperatures.
Journal ArticleDOI
Effect of K and Nd substitutions on superconductivity of Bi2223 superconductors
TL;DR: In this paper, the superconductivity and critical current density of stoichiometric composition Bi1.8Pb0.4Sr2−xKxCa2−yNdyCu3Oz with x = 0, 0.01,0.02, and y = 0.02 were prepared by the solid state reaction method and postannealing experiments were carried out at 500 °C for 30 h in order to improve the oxygen homogeneity.
Journal ArticleDOI
Effect of K-doping to the weak link behaviour of (Cu0.5Tl0.5−xKx)Ba2Ca2Cu3O10−δ superconductors
Nawazish A. Khan,Safeer Hussain +1 more
TL;DR: In this paper, a systematic study of the weak link behavior for (Cu 0.5 Tl 0.25 K 0.6 Tl ) superconductors has been carried out using electrical resistivity and AC-susceptibility techniques, and it is concluded from these studies that potassium atoms appearing at the crystal boundaries enhance inter-grain coupling and pinning mechanism in K-doped (Ba 2 Ca 2 Cu 3 O 10− δ ) supercondors.
Journal ArticleDOI
The (Cu0.5Tl0.5)Ba2O4−δ charge reservoir layer as an efficient source of carriers to the CuO2 planes: Doping of Bi in (Cu0.5Tl0.5)Ba2Ca2Cu3O10−δ superconductors
TL;DR: In this paper, the authors have successfully synthesized (Cu 0.5 Tl 0.25 )Ba 2 O 4− δ charge reservoir layer to the conducting CuO 2 planes.
References
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Journal ArticleDOI
Oxygen nonstoichiometry of 2223 phase Bi-Pb-Sr-Ca-Cu-O system superconducting oxide
TL;DR: In this paper, the effect of PbO content on properties of the 2223 phase was studied by allowing Bismuth to evaporate under 500° C and oxygen 800° C in oxygen of 0.01 atm for different annealing periods.
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Dopant Effects on the Superconductivity in the Bi-Sr-Ca-Cu-O System
TL;DR: The effects of 34 different dopants on the BiSrCaCu2Oy ceramics were investigated in this article, where the dopants can be classified into four categories depending on their solubilities and substitutional properties in the Bi-Sr-Ca-Cu-O structure.
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Effect of Oxygen Content and Sr/Ca Ratio on Superconducting Properties in Bi2Sr2-xCa1+xCu2O8+δ
TL;DR: In this paper, superconducting properties of the 80 K class superconductor in the Bi-Sr-Ca-Cu-O system were examined from the viewpoints of the oxygen content and the Sr/Ca ratio.
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Superconductivity and localisation in the Bi2Sr2Ca1−xRExCu2O8+d(RE = Nd, Sm, Gd and Dy) system
TL;DR: In this paper, the effect of rare earth substitution on the structure, electrical conductivity, and hole concentration of Bi2Sr2CaCu2O8+d was investigated.
Journal ArticleDOI
Dependence of the oxygen isotope effect upon hole density in Bi2Sr2Ca1−xYxCu2O8+δ and Y1−xCaxBa2Cu4O8
TL;DR: In this article, the authors investigated the dependence of the oxygen isotope effect on the hole density in the high T c cuprates Bi 2 Sr 2 CaCu 2 O 8 and YBa 2 Cu 4 O 8.