English
Related papers

Related papers: Evidence for high inter-granular current flow in s…

200 papers

The MgB2 superconductor synthesized in a flowing argon atmosphere using nanometer magnesium powder as the raw materials, denoted as Nano-MgB2, has been studied by the technique of in-situ high temperature resistance measurement (HT-RT…

Superconductivity · Physics 2009-11-10 Chinping Chen , Zeng-jun Zhou , Xing-guo Li , Jun Xu , Yu-hao Wang , Yong-zhong Wang , Qing-rong Feng

In order to increase the accelerating gradient of Superconducting Radio Frequency (SRF) cavities, Magnesium Diboride (MgB2) opens up hope because of its high transition temperature and potential for low surface resistance in the high RF…

Superconductivity · Physics 2015-06-04 Tamin Tai , Behnood G. Ghamsari , Steven M. Anlage , C. G. Zhuang , X. X. Xi

The recently-discovered MgB2 super-conductor has a transition temperature Tc approaching 40K, placing it intermediate between the families of low and high temperature super-conductors (LTS and HTS). In practical applications,…

Superconductivity · Physics 2007-05-23 Y. Bugoslavsky , G. K. Perkins , X. Qi , L. F. Cohen , A. D. Caplin

The anisotropy of the critical current density (Jc) and its influence on measurement of irreversibility field (Birr) has been investigated for high quality, in-situ MgB2 strands. Comparison of transport and magnetization measurements has…

Superconductivity · Physics 2015-05-14 Z. X. Shi , M. A. Susner , M Majoros , M. D. Sumption , X. Peng , M. Rindfleisch , M. J. Tomsic , E. W. Collings

Highly dense nanocrystalline MgB_2 bulk superconductors with distinctly improved pinning were prepared by mechanical alloying of Mg and B powders and hot compaction at ambient temperatures. The nanocrystalline samples reveal high critical…

Superconductivity · Physics 2009-11-07 A. Gümbel , J. Eckert , G. Fuchs , K. Nenkov , K. -H. Müller , L. Schultz

The present article reports a method for the average grain size evaluation of superconducting nano-particles through their magnetic properties. The use of SQUID magnetometry to determine the average MgB2 particle size was investigated and…

The superconducting phase diagram of MgB2 was determined from magnetization, magneto-transport and the first single-crystal specific heat measurements. A zero-temperature in-plane coherence length of 8 nm is determined. The superconducting…

We synthesized single crystalline and policrystalline MgB_2 under ambient pressures. The single crystals of MgB_2 were of good quality, where the crystal structure refinements were successfully converged with R = 0.020. The specific heat of…

Superconductivity · Physics 2009-11-07 Y. Machida , S. Sasaki , H. Fujii , M. Furuyama , I. Kakeya , K. Kadowaki

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

The high transition temperature and low surface resistance of MgB2 attracts interest in its potential application in superconducting radio frequency accelerating cavities. However, compared to traditional Nb cavities, the viability of MgB2…

Superconductivity · Physics 2013-09-09 Tamin Tai , B. G. Ghamsari , T. Tan , C. G. Zhuang , X. X. Xi , Steven M. Anlage

Ex-situ Powder-In-Tube MgB2 tapes prepared with ball-milled, undoped powders showed a strong enhancement of the irreversibility field H*, the upper critical field Hc2 and the critical current density Jc(H) together with the suppression of…

The high resistivity of many bulk and film samples of MgB2 is most readily explained by the suggestion that only a fraction of the cross-sectional area of the samples is effectively carrying current. Hence the supercurrent (Jc) in such…

Superconductivity · Physics 2009-11-10 J. M. Rowell , S. Y. Xu , X. H. Zeng , A. V. Pogrebnyakov , Q. Li , X. X. Xi , J. M. Redwing , W. Tian , X. Pan

The superconducting properties of copper-sheathed MgB2 wires fabricated by conventional powder-in-tube techniques and the in-situ reaction procedure are analysed. The influence of the processing conditions and initial (1+x)Mg + 2B (x = 0,…

Superconductivity · Physics 2007-05-23 E. Martinez , R. Navarro

We report on tunneling spectroscopy experiments in small grains of the new binary intermetallic superconductor MgB2. Experiments have been performed at 2.5 K using a low temperature scanning tunneling microscope. Good fit to the BCS model…

Superconductivity · Physics 2009-11-07 Gabino Rubio-Bollinger , Hermann Suderow , Sebastian Vieira

Studies on the new MgB2 superconductor, with a critical temperature Tc ~ 39 K, have evidenced its potential for applications although intense magnetic relaxation effects limit the critical current density, Jc, at high magnetic fields. This…

Superconductivity · Physics 2009-11-07 O. F. de Lima , C. A. Cardoso , R. A. Ribeiro , M. A. Avila , A. A. Coelho

Superconducting MgB2 thin films were prepared on Al2O3(0001) and MgO(100) substrates. Boron thin films were deposited by the electron-beam evaporation followed by post-annealing process with magnesium. Proper post annealing conditions were…

Superconductivity · Physics 2009-11-07 S. H. Moon , J. H. Yun , H. N. Lee , J. I. Kye , H. G. Kim , W. Chung , B. Oh

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

Studies of the behaviour of solids at ultra-high pressures, those beyond 200 GPa, contribute to our fundamental understanding of materials properties and allow an insight into the processes happening at such extreme conditions relevant for…

Ultrathin sheets of MoS2 are a newly discovered 2D semiconductor that holds great promise for nanoelectronics. Understanding the pattern of current flow will be crucial for developing devices. In this talk, we present images of current flow…

Mesoscale and Nanoscale Physics · Physics 2017-09-13 Sagar Bhandari , Ke Wang , Kenji Watanabe , Takashi Taniguchi , Philip Kim , Robert M. Westervelt

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…