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Related papers: Enhancement of Jc by Hf -Doping in the Superconduc…

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A strong effect of sample size on magnetic Jc(H) was observed for bulk MgB2 when Jc is obtained directly from the critical state model. Thus obtained zero-field Jc (Jc0) decreases strongly with the sample size, attaining a constant value…

Superconductivity · Physics 2007-05-23 J. Horvat , S. Soltanian , X. L. Wang , S. X. Dou

We report magnetic field dependent magnetization and microwave impedance measurements on a MgB2 superconductor prepared by high pressure synthesis. We find that the upper critical field is linearly dependent on temperature near Tc and the…

Superconductivity · Physics 2009-11-07 A. Dulcic , D. Paar , M. Pozek , G. V. M. Williams , S . Kramer , C. U. Jung , Min-Seok Park , Sung-Ik Lee

It has been shown that graphene doping is sufficient to lead to an improvement in the critical current density - field performance (Jc(B)), with little change in the transition temperature in MgB2. At 3.7 at% graphene doping of MgB2 an…

Superconductivity · Physics 2015-05-18 X. Xu , S. X. Dou , X. L. Wang , J. H. Kim , J. A. Stride , M. Choucair , W. K. Yeoh , R. K. Zheng , S. P. Ringer

Critical current density (Jc) is one of the major limiting factors for high field applications of iron-based superconductors. Here, we report that Mn-ions are successfully incorporated into nontoxic superconducting (Li,Fe)OHFeSe films.…

We have studied the local critical current density, jc, in the superconductor thin film of bilayer structures consisting of YBa2Cu3O7 and the ferromagnets La2/3Ca1/3MnO3 and SrRuO3, respectively, by means of quantitative magneto-optics. A…

Superconductivity · Physics 2009-11-10 H. -U. Habermeier , J. Albrecht , S. Soltan

In the present study, La-doped MgB_2 superconductors with different doping level (Mg1-xLaxB2; x=0.00, 0.01, 0.03 & 0.05) have been synthesized by solid-state reaction route at ambient pressure. Effect of La doping have been investigated in…

Materials Science · Physics 2007-05-23 Chandra Shekhar , Rajiv Giri , R S Tiwari , D S Rana , S K Malik , O N Srivastava

We investigated the effect of SiC nano-particle doping on the crystal lattice structure, critical temperature T_c, critical current density J_c, and flux pinning in MgB_2 superconductor. A series of MgB_{2-x}(SiC)_{x/2} samples with x = 0…

Superconductivity · Physics 2007-05-23 S. X. Dou , A. V. Pan , S. Zhou , M. Ionescu , X. L. Wang , J. Horvat , H. K. Liu , P. R. Munroe

We investigate the in-field critical current density Jc(B) of SNS Josephson Junctions (JJs) and polycrystalline superconductors with grain boundaries modelled as Josephson type planar defects, both analytically and through computational…

Superconductivity · Physics 2021-10-06 A. I. Blair , D. P. Hampshire

The upper critical field Hc2(T) of sintered pellets of the recently discovered MgB_2 superconductor was investigated in magnetic fields up to 16 T. The upper critical field of the major fraction of the investigated sample was determined…

Superconductivity · Physics 2014-10-13 K. -H. Müller , G. Fuchs , A. Handstein , K. Nenkov , V. N. Narozhnyi , D. Eckert

Large area arrays of through-thickness nanoscale pores have been milled into superconducting Nb thin films via a process utilizing anodized aluminum oxide thin film templates. These pores act as artificial flux pinning centers, increasing…

We present electrical transport, magnetization, and specific heat measurements on bulk MgB2 samples (T_{c} = 38.5 K) synthesized under 200 MPa pressure using a process based on hot isostatic pressing with cooling under pressure. The samples…

Superconductivity · Physics 2009-11-07 N. A. Frederick , Shi Li , M. B. Maple , V. F. Nesterenko , S. S. Indrakanti

Nanoscale defects in superconductors play a dominant role in enhancing superconducting properties through electron scattering, modulation of coherence length, and correlation with quantized magnetic flux. For iron-based superconductors…

Superconductivity · Physics 2019-11-22 Shinnosuke Tokuta , Akiyasu Yamamoto

The effect of nanoscale-SiC doping of MgB2 was investigated using transport and magnetic measurements. It was found that there is a clear correlation between the critical temperature Tc, the resistivity r, the residual resistivity ratio,…

Superconductivity · Physics 2009-11-10 S. X. Dou , V. Braccini , S. Soltanian , R. Klie , Y. Zhu , S. Li , X. L. Wang , D. Larbalestier

We have fabricated a series of ex situ copper sheathed powder-in-tube MgB2 wires with 20% by volume Ag, Pb, In, and Ga metal added to the MgB2 powder. We find the transport critical current of these wires increases significantly with the…

Superconductivity · Physics 2009-11-11 M. J. Holcomb

This work studies the influence of microstructures and crystalline defects on the superconductivity of MgB2, with the objective to improve its flux pinning. A MgB2 sample pellet that was hot isostatic pressed (HIPed) was found to have…

We study the effect of neutron irradiation on the critical current density Jc of isotopically pure polycrystalline Mg11B2 samples. For fluences in the range 1017-1018 cm-2, Jc is enhanced and its dependence on magnetic field is…

The DC magnetization and AC complex magnetic susceptibilities were measured for MgB2 single crystals, unsubstituted and carbon substituted with the composition of Mg(B_0.94C_0.06)2. The measurements were performed in AC and DC magnetic…

Superconductivity · Physics 2011-01-14 M. Ciszek , K. Rogacki , K. Oganisian , N. D. Zhigadlo , J. Karpinski

We have studied structural and superconducting properties of MgB2 thin films doped with carbon during the hybrid physical-chemical vapor deposition process. A carbon-containing metalorganic precursor bis(cyclopentadienyl)magnesium was added…

The upper critical field Hc2(T) of sintered pellets of the recently discovered MgB_2 superconductor was investigated by transport, ac susceptibility and dc magnetization measurements in magnetic fields up to 16 T covering a temperature…

Superconductivity · Physics 2009-11-07 G. Fuchs , K. -H. Müller , A. Handstein , K. Nenkov , V. N. Narozhnyi , D. Eckert , M. Wolf , L. Schultz

Monocore powder-in-tube MgB2 strands were cold-drawn and heat-treated at 600C and 700C for times of up to 71 hours and structure-property relationships examined. Drawing-induced elongation of the Mg particles led, after HT, to a textured…

Superconductivity · Physics 2015-05-30 M. A. Susner , T. W. Daniels , M. D. Sumption , E. W. Collings