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Related papers: MgB2 bulk superconducting magnet

200 papers

We report synthesis, structure/micro-structure, resistivity under magnetic field [R(T)H], Raman spectra, thermoelectric power S(T), thermal conductivity K(T), and magnetization of ambient pressure argon annealed polycrystalline bulk samples…

Superconductivity · Physics 2015-05-13 V. P. S. Awana , Arpita Vajpaye , Monika Mudgel , H. Kishan , V. Ganesan , A. M. Awasthi , G. L. Bhalla

We report the fabrication of MgB2 with bulk superconducting properties by conventional solid state methods at temperatures as low as 550 C. Mg deficiencies of the type Mg1-xB2 were tested. Tc was found to decrease by about 1K at large x,…

Superconductivity · Physics 2009-11-07 N. Rogado , M. A. Hayward , K. A. Regan , Yayu Wang , N. P. Ong , John M. Rowell , R. J. Cava

The ability of stacks of superconducting tapes to trap large magnetic fields makes them ideal candidates for creating powerful permanent magnets of compact size and mass. Experimentally, several techniques are used to trap the maximum…

Superconductivity · Physics 2016-06-07 Víctor M. R. Zermeño , Algirdas Baskys , Shengnan Zou , Anup Patel , Francesco Grilli

The fabrication, characterisation, and superconductivity of MgB2 thick films grown on stainless steel substrate were studied. XRD, SEM, and magnetic measurements were carried out. It was found that the MgB2 thick films can be fast formed by…

Superconductivity · Physics 2007-05-23 A. H. Li , X. L. Wang , M. Ionescu , S. Soltonian , J. Horvat , T. Silver , H. K. Liu , S. X. Dou

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

We report on magnetic and magnetoresistance measurements in two categories of superconducting Nb films grown via magnetron sputtering and MgB2 bulk samples. In the first category, films of Tc = 9.25 K were produced by annealing during…

Superconductivity · Physics 2009-11-10 Dimosthenis Stamopoulos , Athanasios Speliotis , Dimitris Niarchos

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

Transport current values of 7.5 x 104 A/cm2 at 4.2 K and self-field are reported for MbB2-based tapes. MgB2 strands were formed by directly filling commercially available MgB2 powder into Nb-lined, monel tubes and wire drawing. The wires…

Superconductivity · Physics 2007-05-23 M. D. Sumption , X. Peng , E. Lee , M. Tomsic , E. W. Collings

We characterize the superconducting state of phase pure polycrystalline samples of the new layered superconductor MgB$_2$ by specific heat measurements in magnetic fields up to 9 T. The characteristic jump at the superconducting transition…

Superconductivity · Physics 2007-05-23 R. K. Kremer , B. J. Gibson , K. Ahn

We present scanning tunneling microscopy measurements of the surface of superconducting MgB2 with a critical temperature of 39K. In zero magnetic field the conductance spectra can be analyzed in terms of the standard BCS theory with a…

Superconductivity · Physics 2009-11-07 G. Karapetrov , M. Iavarone , W. K. Kwok , G. W. Crabtree , D. G. Hinks

The fluctuating diamagnetic magnetization Mfl at constant field H as a function of temperature and the isothermal magnetization Mfl vs H are measured in MgB2, above the superconducting transition temperature. The expressions for Mfl in…

Superconductivity · Physics 2009-11-07 A. Lascialfari , T. Mishonov , A. Rigamonti , P. Tedesco , A. Varlamov

In-plane electrical transport properties of MgB2 single crystals grown under high pressure of 4-6 GPa and temperature of 1400-1700oC in Mg-B-N system have been measured. For all specimens we found sharp superconducting transition around…

Superconductivity · Physics 2009-11-07 Yu. Eltsev , S. Lee , K. Nakao , N. Chikumoto , S. Tajima , N. Koshizuka , M. Murakami

The paper reports the first successful fabrication of MgB2 superconducting tape using a flexible metallic substrate as well as its strong pinning force, which was verified by direct measurement of transport critical current density. The…

Superconductivity · Physics 2009-11-07 K. Komori , K. Kawagishi , Y. Takano , H. Fujii , S. Arisawa , H. Kumakura , M. Fukutomi , K. Togano

According to the crystal structure of MgB$_{2}$ and band structure calculations quasi-two-dimensional (2D) boron planes are responsible for the superconductivity. We report on critical fields and resistance measurements of 30 nm thick…

Superconductivity · Physics 2009-11-07 A. S. Sidorenko , L. R. Tagirov , A. N. Rossolenko , V. V. Ryazanov , R. Tidecks

We present the fabrication and test results of Hot-Isostatic-Pressed (HIPed) Powder-in-Tube (PIT) MgB$_2$ coils. The coils properties were measured by transport and magnetization at different applied fields ($H$) and temperatures ($T$). The…

The recent discovery of intermediate-temperature superconductivity (ITC) in MgB2 by Akimitsu et al. and its almost simultaneous explanation in terms of a hole-carrier-based pairing mechanism by Hirsch, has triggered an avalanche of studies…

Superconductivity · Physics 2009-11-07 S. X. Dou , X. L. Wang , J. Horvat , D. Milliken , E. W. Collings , M. D. Sumption

Magnetisation of superconductors are often measured under isothermal and uniform magnetic fields. Magnetisation measurements in an unrestricted thermodynamic state and in non uniform magnetic fields naturally emerge from permanent magnets…

Superconductivity · Physics 2019-08-28 Nithin Goona , P. S. Reddy , S. Sashidhar

Dense pure and doped (Mg1-xAx)B2 samples with A = Na, Ca, Cu, Ag, Zn and Al were synthesized at high pressure - high temperature in a multi anvils press (3.5-6 GPa, 900-1000C) for x up to 0.20. They were studied by x-ray diffraction,…

Superconductivity · Physics 2007-05-23 P. Toulemonde , N. Musolino , H. L. Suo , R. Flukiger

We have performed a comparative study of two thin films of magnesium diboride (MgB2) grown by different techniques. The critical current density at different temperatures and magnetic fields was evaluated from magnetisation curves, the…

$MgB_2$ becomes superconducting just below 40 K. Whereas porous polycrystalline samples of $MgB_2$ can be synthesized from boron powders, in this letter we demonstrate that dense wires of $MgB_2$ can be prepared by exposing boron filaments…