Journal ArticleDOI
Influence of the Tl- and Hg-content on magnetic and transport properties of the Pb, Sr-doped Tl-1223 and Hg-1223 superconductors
TLDR
In this paper, the effects of thallium and mercury content x on the as-sintered and post annealed samples of M x Pb 0.4 Sr 1.6 Ba 0.Abstract:
The effects of the thallium and mercury content x on the as-sintered and post annealed samples of M x Pb 0.4 Sr 1.6 Ba 0.4 Ca 2 Cu 3 O 8+ δ {M: Tl (0.32≤ x ≤0.74) or Hg (0.18≤ x ≤0.68)} have been studied by magnetization and transport measurements. For Tl-1223 we have found the optimum Tl doping level to be x =0.53 regarding the grain properties, the content of superconducting phase, the first penetration field H pl wl , the transport ( J c tr ), magnetic intergrain ( J c M ) and intragrain ( J c g ) critical current densities. The critical temperature T c of the as-sintered Tl-1223 sample decreased with increasing Tl content. Post-annealing in oxygen improved the T c for Tl contents of x ≥0.53 and had generally positive effects on the critical current densities. The intergrain properties of the Hg-1223 samples were much worse than those of the Tl-based superconductors.read more
Citations
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Journal ArticleDOI
The morphology, periodical modulation structure and effects of heat treatment on the superconductivity of (Tl, Pb)(Sr, Ba)-1223 single crystals
Zhenxiang Cheng,Zhenxiang Cheng,X.L. Wang,S. Keshavarzi,M. J. Qin,T. Silver,H.K. Liu,H Kimura,Shi Xue Dou +8 more
TL;DR: In this article, surface morphologies and microstructures of (Tl, Pb)(Sr, Ba)-1223 single crystals were investigated using a scanning electronic microscope (SEM) and an atomic force microscope (AFM).
Journal ArticleDOI
Excess Conductivity and Superconducting Fluctuation Analysis of Cr-Substituted Tl-1223 Type Phase (Tl 1−x Cr x )Ba 2 Ca 2 Cu 3 O 9−δ (x = 0.4–0.8)
M. G. Ranjbar,Roslan Abd-Shukor +1 more
TL;DR: In this paper, the Aslamazov-Larkin (AL) theory was used to investigate the dimension of fluctuation-induced conductivity λ, and the coherence length and anisotropy of the samples were calculated by using the Lawrence-Doniach (LD) theory.
Journal ArticleDOI
Formation of Tl-1223 phase in Cr substituted (Tl1−xCrx)Ba2Ca2Cu3O9−δ (x=0.3 to 0.9) superconductor
M.G. Ranjbar,Roslan Abd-Shukor +1 more
TL;DR: In this article, the effect of Cr substitution on the formation of Tl-1223 type phase is reported, and it is shown that the (Tl,Cr)-1223 phase can be stabilized with Cr substitutions without the use of Sr.
Journal ArticleDOI
Long-term stability of Hg-based cuprate superconducting thin films prepared from a fluoride precursor
TL;DR: In this article, the long-term stability of superconducting properties of Hg-based cuprate thin films is studied using x-ray diffraction patterns and their electrical properties.
References
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Journal ArticleDOI
Anisotropic critical currents in Ba2YCu3O7 analyzed using an extended Bean model
TL;DR: In this paper, the authors extended the critical state model to explicitly include anisotropic critical currents and showed that current flow perpendicular to the Cu-O planes is about 30 times smaller than flow parallel to these planes.
Journal ArticleDOI
Structures of High‐Temperature Cuprate Superconductors
Chan Park,Robert L. Snyder +1 more
TL;DR: Most of the known cuprate superconductors are shown to belong structurally to a single family and are closely related to each other as discussed by the authors, which leads to three significant insights into the nature of, and requirements for, superconductivity in these phases: (1) a nearly planar sheet of CuO{sub 2} supports the supercurrent; (2) as the distance between the n ACuO{ sub 2} blocks in a crystal structure increases, the critical current density decreases at high reduced temperatures due to the magnetic flux lines becoming unpinned; (
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The synthesis and characterization of HgBa2Ca2Cu3O8+δ superconductors with substitution of Hg by Pb
H.M. Shao,H.M. Shao,C.C. Lam,P.C.W. Fung,X.S. Wu,J. H. Du,G.J. Shen,James C. L. Chow,S.L. Ho,K.C. Hung,Xixian Yao,Xixian Yao +11 more
TL;DR: In this article, the authors have successfully fabricated ceramic superconductors of Hg-1223 with substitution of Pb for Hg, i.e. Hg1−xPbxBa2Ca2Cu3Oy, by using encapsulation and short time annealing techniques.
Journal ArticleDOI
Geometrical and distributed surface barriers in Bi2Sr2CaCu2O8
TL;DR: In this paper, the local magnetic response in Bi 2 Sr 2 CaCu 2 O 8 crystals of platelet and prism shapes has been measured using microscopic arrays of Hall sensors and models for the local ac response are derived for the two cases.
Journal ArticleDOI
Fluorination of mercury-based high-temperature superconductors
TL;DR: In this article, the effect of fluorine incorporation by this route appears to mimic the more usual oxygenation process in giving maximum T c values of 96, 128 and 135 K for the single, double and triple CuO 2 -layer materials, respectively.