A Search for a Low Anisotropic Superconductor

Khurram, A. A.; Khan, Nawazish A.

doi:10.4236/jemaa.2010.22010

Cited by 5 publications

(2 citation statements)

References 110 publications

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“…The high-pressure and high-temperature synthesized CuBa 2 Ca 3 Cu 4 O 10+δ (Cu-1234) system is intensively studied, because of its relatively high superconducting transition temperature T c of about 116 K at the ambient pressure together with its low crystallographic anisotropy and lack of toxic elements [ 14 , 15 , 16 ], which are crucial if we have to deal with the utilization of this material in devices. The above mentioned facts, as well as a high value of the critical current density j c of the order of 10 4 A/cm 2 at 77 K [ 17 ], make the Cu-1234 system a cut above other groups in the cuprate family of high-temperature superconductors (HTSCs) from the device-production perspective.…”

Section: Introductionmentioning

confidence: 99%

Superconducting State Properties of CuBa2Ca3Cu4O10+δ

et al. 2023

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The superconducting state properties of the CuBa2Ca3Cu4O10+δ (Cu-1234) system, with a transition temperature as high as 117.5 K, were investigated. The ac magnetic susceptibility measurements confirmed a very sharp transition to the superconducting state. The upper critical field, Hc2, as high as 91 T, and the irreversibility field, Hirr, as high as 21 T at 77 K, were determined using dc SQUID magnetization measurements. The intragrain critical current density, jc, estimated from a magnetic hysteresis loop, is as high as 5 × 109 A/m2 in a self-generated magnetic field at 77 K. However, the intergrain critical current density in the studied material is smaller by four orders of magnitude due to very weak intergrain connections.

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Section: Introductionmentioning

confidence: 99%

Superconducting State Properties of CuBa2Ca3Cu4O10+δ

et al. 2023

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“…Although similar oxides have revealed superconductors at temperatures as low as 30 K, Tc (transition temperatures) of later cuprates is almost an order of magnitude higher than any previously known superconductor [1][2][3]. In spite 33 years of research, no consent has arisen on causes of superconductivity in copper oxides [4][5]. As a result, main emphasis is on knowing the physical origin of the new Properties of the normal state in the expectation that these may provide signi cant insight into the advent of superconductivity at such high temperature.…”

Section: Introductionmentioning

confidence: 99%

Possible Sources of Trigger Mechanism of Electron-phonon Interactions in Doped CuTl-1223 Superconductors

Kanwal¹,

Khan²

2021

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This article underlines the important role of copper Cu(3d9) spins at the CuO2 planer sites to comprehend the physics of High temperature Superconductivity . In such studies we have reported the characterization results of samples (Cu0.5Tl0.5)Ba2Ca2Cu3O10-δ , (Cu0.5Tl0.5)(BaCa)(CaMg)Cu1Zn2O10-δ , (Cu0.5Tl0.5)(BaCa)(CaMg) Zn3O10-δ and (AyTl1-y)(BaCa)(CaMg) Zn3O10-δ (A=Ag, K, Ni, Mn; y=0,0.5). Samples were prepared at normal pressure by using two-steps solid state reaction method. The characterization of samples is done via x-ray diffraction (XRD), resistivity (RT) and Fourier Transform Infrared (FTIR) absorption measurements. Intrinsic superconducting parameters and activation energy of all sample is estimated applying two theoretical models, Fluctuation Induced conductivity (FIC) analysis and Mott 3D-VRH. The XRD and FTIR absorption measurements have confirmed the intrinsic doping of K, Ag, Ni, Mn and Zn. Interestingly, samples (Cu0.5Tl0.5)(BaCa)(CaMg) Zn3O10-δ without CuO2 planes have exhibited superconducting behavior above 77K. To verify the role of Cu(3d9) atoms in superconductivity we have synthesized (AyTl1-y)(BaCa)(CaMg) Zn3O10-δ (A=Ag, K, Mn, Ni; y=0,0.5) samples. In aforementioned samples, doping of Ni, Mn, K, Ag ions in Cu1-xTlxBa2O4-δ charge reservoir layer instead of Cu-atoms destroys the superconductivity completely and leads to semiconducting behavior. Key objective to preparing these samples is to investigate the role of two major parameters local moments (spin) of copper atoms and net carrier’s concentration in superconductivity.

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