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Related papers: Boron Isotope Effect in Superconducting MgB$_2$

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Growth of carbon substituted magnesium diboride Mg(B1-xCx)2 single crystals with 0<x<0.15 is reported and the structural, transport, and magnetization data are presented. The superconducting transition temperature decreases monotonically…

We study the effect of synthesis temperature on the phase formation in nano(n)-SiC added bulk MgB2 superconductor. In particular we study: lattice parameters, amount of carbon (C) substitution, microstructure, critical temperature (Tc),…

Superconductivity · Physics 2015-05-27 Arpita Vajpayee , R. Jha , A. K. Srivastava , H. Kishan , M. Tropeano , C. Ferdeghini , V. P. S. Awana

The recently discovered superconductivity in MgB2 has created the world sensation. In spite of the relatively high superconducting transition temperature Tc=39K, the superconductivity is understood in terms of rare two gap superconductor…

Superconductivity · Physics 2007-05-23 T. Dahm , A. I. Posazhennikova , K. Maki

This paper reports specific-heat measurements on superconducting MgB2 in magnetic fields to 9 T. In zero magnetic field the data can be fitted to a two-gap model, which is a generalization of a semi-empirical model for strong-coupled,…

Superconductivity · Physics 2007-05-23 R. A. Fisher , F. Bouquet , N. E. Phillips , D. G. Hinks , J. D. Jorgensen

The recent surprising discovery of superconductivity with critical temperature $T_c$ = 32 K in MoB$_2$ above 70 GPa has led to the search for related materials that may superconduct at similarly high $T_c$ values and lower pressures. We…

We synthesized polycrystalline MgB2 from a stoichiometric mixture of Mg and the 11 B isotope under different conditions. All the samples showed bulk superconductivity with Tc = 38~39 K. The samples containing the least amount of unreacted…

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

MgB2 is a promising superconductor for important large-scale applications for both high field magnets and cryocooler-cooled magnet operated at temperatures around 20 K. In this work, by utilizing C60 as a viable alternative dopant, we…

Superconductivity · Physics 2009-11-13 Xianping Zhang , Yanwei Ma , Zhaoshun Gao , Dongliang Wang , Lei Wang , Wei Liu , Chunru Wang

We studied the effect of disorder on the superconducting properties of polycrystalline MgB_2 by specific-heat measurements. In the pristine state, these measurements give a bulk confirmation of the presence of two superconducting gaps with…

The superconductivity in the Bi-II phase of elemental Bismuth (transition temperature $T_{\rm c}\simeq3.92$ K at pressure $p\simeq 2.80$ GPa) was studied experimentally by means of the muon-spin rotation as well as theoretically by using…

A recent work has demonstrated that MoB$_2$, transforming to the same structure as MgB$_2$ ($P6/mmm$), superconducts at temperatures above 30 K near 100 GPa [C. Pei $et$ $al$. Natl. Sci. Rev., nwad034 (2023)], and Nb-substitution in MoB$_2$…

We report the effect of the sintering temperature on the superconductivity of MgB2 pellets prepared under a high pressure of 3 GPa. The superconducting properties of the non-heated MgB2 in this high pressure were poor. However, as the…

Superconductivity · Physics 2009-11-07 C. U. Jung , Min-Seok Park , W. N. Kang , Mun-Seog Kim , Kijoon H. P. Kim , S. Y. Lee , Sung-Ik Lee

The tetragonal Mo$_5$PB$_2$ compound was recently reported to show superconductivity with a critical temperature up to 9.2 K. In search of evidence for multiple superconducting gaps in Mo$_5$PB$_2$, comprehensive measurements, including…

Superconductivity · Physics 2020-09-09 T. Shang , W. Xie , D. J. Gawryluk , R. Khasanov , J. Z. Zhao , M. Medarde , M. Shi , H. Q. Yuan , E. Pomjakushina , T. Shiroka

The dependence of Tc for MgB2 on purely hydrostatic or nearly hydrostatic pressure has been determined to 23 GPa for single-crystalline and to 32 GPa for polycrystalline samples, and found to be in good agreement. Tc decreases from 39 K at…

From first-principles calculations, we predict four new intercalated hexagonal $X$BC ($X$=Mg, Ca, Sr, Ba) compounds to be dynamically stable and phonon-mediated superconductors. These compounds form a LiBC like structure but are metallic.…

Superconductivity · Physics 2022-05-10 Enamul Haque , M. Anwar Hossain , Catherine Stampfl

With the motivation of searching for new superconductors in the Mg-B system, we performed ab initio evolutionary searches for all the stable compounds in this binary system in the pressure range of 0-200 GPa. We found previously unknown,…

Superconductivity · Physics 2017-05-24 M. M. Davari Esfahani , Q. Zhu , H. Dong , A. R. Oganov , S. Wang , M. S. Rakitin , X-F. Zhou

The normal state and superconducting properties of MgB2 and Mg1-xAlxB2 are discussed based on structural, transport, and high pressure experiments. The positive Seebeck coefficient and its linear temperature dependence for Tc<T<160 K…

Superconductivity · Physics 2007-05-23 B. Lorenz , Y. Y. Xue , R. L. Meng , C. W. Chu

We address the effect of MgO impurity on the superconducting properties of MgB2. The synthesis of MgB2 is very crucial because of sensitivity of Mg to oxidation which may lead to MgO as a secondary phase. Rietveld refinement was performed…

Superconductivity · Physics 2015-06-19 Dharmendra Kumar Singh , Brajesh Tiwari , Rajveer Jha , H. Kishan , V. P. S. Awana

MgB2 hollow wires have been produced with a new technique which uses a conventional wire manufacturing process but is applied to composite billets containing the elemental B and Mg precursors in an appropriate shape. The technique has been…

Superconductivity · Physics 2009-11-07 G. Giunchi , S. Ceresara , G. Ripamonti , A. DiZenobio , S. Rossi , S. Chiarelli , M. Spadoni , R. Wesche , P. L. Bruzzone

We report on a hierarchy of temperatures Tc < Tgap < Tmet in superconducting Rb1-xFe2-ySe2 observed by THz spectroscopy. Above Tmet = 90 K the material reveals semiconducting characteristics. Below Tmet a coherent metallic THz response…

Superconductivity · Physics 2014-03-05 Zhe Wang , M. Schmidt , J. Fischer , V. Tsurkan , M. Greger , D. Vollhardt , A. Loidl , J. Deisenhofer