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Related papers: A first-principles study of MgB2 (0001) surfaces

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The electronic properties of the surface of $\beta$-FeSi$_2$ have been debated for a long while. We studied the surface states of $\beta$-FeSi$_2$ films grown on Si(001) substrates using scanning tunnelling microscopy (STM) and spectroscopy…

Materials Science · Physics 2023-02-16 Keisuke Sagisaka , Tomoko Kusawake , David Bowler , Shinya Ohno

The structural properties of MgB2 superconductors have been analyzed by means of convergent-beam electron diffraction, high-resolution transmission-electron microscopy, and theoretical simulations. The MgB2 crystal has been identified to…

Superconductivity · Physics 2007-05-23 J. Q. Li , L. Li , Y. Q. Zhou , Z. A. Ren , G. C. Che , Z. X. Zhao

The MgB2 bulks were prepared by high energy milling of Mg and B powder. The correlations among milling times, microstructure and superconducting properties were investigated in MgB2 bulks. Samples were characterized by x-ray diffraction…

Superconductivity · Physics 2008-01-14 Y. F. Wu , Y. F. Lu , G. Yan , J. S. Li , Y. Feng , H. P. Tang , S. K. Chen , H. L. Xu , C. S. Li , P. X. Zhang

Based on a detailed modeling of the Fermi surface topology of MgB2 we calculated the anisotropy of the upper critical field Bc2 within the two gap model. The sigma-band is modeled as a distorted cylinder and the pi-band as a half-torus,…

Superconductivity · Physics 2007-05-23 T. Dahm , S. Graser , N. Schopohl

Polarization-dependent x-ray absorption spectroscopy at the B 1s edge of single-crystalline Mg(x)Al(1-x)B(2) reveals a strongly anisotropic electronic structure near the Fermi energy. Comparing spectra for superconducting compounds (x=0.9,…

The microstructure of the MgB2 superconductor sintered at high temperature under a high pressure of about 3 GPa was investigated by using a high-resolution transmission electron microscope (HRTEM). The TEM images did not show any pores in…

The high-pressure synthesis is one of the most promising methods to produce MgB2 superconductive (SC) material. The available high-pressure apparatuses have working volume up to 100 cm3 which allows samples up to 60 mm in diameter to be…

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

We present the results of the first directional point-contact spectroscopy experiments in high-quality MgB_2 single crystals. Due to the directionality of the current injection into the samples, the application of a magnetic field allowed…

Superconductivity · Physics 2009-11-07 R. S. Gonnelli , D. Daghero , G. A. Ummarino , V. A. Stepanov , J. Jun , S. M. Kazakov , J. Karpinski

We model the normal state of ferromagnetic superconductors with two general ellipsoidal Fermi surfaces (FSs), one for each spin projection $\sigma=\{\uparrow,\downarrow\}$, each with its ferromagnetically split chemical potential…

Superconductivity · Physics 2014-04-01 Christopher Lörscher , Jingchuan Zhang , Qiang Gu , Richard A. Klemm

High-resolution angle-resolved photoemission spectroscopy has been performed on Sb(111) to elucidate the origin of anomalous electronic properties in group-V semimetal surfaces. The surface was found to be metallic despite the semimetallic…

Other Condensed Matter · Physics 2009-11-11 K. Sugawara , T. Sato , S. Souma , T. Takahashi , M. Arai , T. Sasaki

Thermodynamic properties of the multiband superconductor MgB$_{2}$ have often been described using a simple sum of the standard BCS expressions corresponding to $\sigma$- and $\pi$-bands. Although, it is \textit{a priori} not clear if this…

Superconductivity · Physics 2009-11-11 Oleg V. Dolgov , Reinhard K. Kremer , Jens Kortus , Alexander A. Golubov , Sergei V. Shulga

MgB2 superconducting wires with critical temperature Tc approaching 40 K were used for preparation of MgB2/Ag and MgB2/In junctions. The differential conductance vs. voltage characteristics of N-S junctions exhibit clear contribution of…

Superconductivity · Physics 2009-11-07 A. Plecenik , S. Benacka , P. Kus , M. Grajcar

As-grown superconducting thin films of MgB2 were prepared by molecular beam epitaxy (MBE), and studied by X-ray and ultraviolet photoelectron spectroscopy (XPS and UPS). Only films prepared at temperatures between 150 and 320 deg. showed…

Superconductivity · Physics 2009-11-07 K Ueda , H. Yamamoto , M. Naito

We study the new binary intermetallic superconductor MgB2 using high-resolution photo-emission spectroscopy. The superconducting-state spectrum measured at 5.4 K shows a coherent peak with a shoulder structure, in sharp contrast to that…

Superconductivity · Physics 2009-11-07 S. Tsuda , T. Yokoya , T. Kiss , Y. Takano , K. Togano , H. Kitou , H. Ihara , S. Shin

The surface impedance of Nb/CuMn (superconducting/spin-glass) bilayers has been measured at 10 GHz with the parallel plate resonator technique to obtain information about the exotic behavior of the order parameter in…

Superconductivity · Physics 2009-10-31 L. V. Mercaldo , Steven M. Anlage , L. Maritato

We have performed high-resolution angle-resolved photoemission spectroscopy on heavily overdoped KFe_2As_2 (transition temperature (Tc = 3 K). We observed several renormalized bands near the Fermi level with a renormalization factor of 2-4.…

Superconductivity · Physics 2015-05-13 T. Sato , K. Nakayama , Y. Sekiba , P. Richard , Y. -M. Xu , S. Souma , T. Takahashi , G. F. Chen , J. L. Luo , N. L. Wang , H. Ding

Tunneling data on magnesium diboride, MgB_2, are reviewed with a particular focus on superconductor-insulator-superconductor (SIS) junctions formed by a break-junction method. The collective tunneling literature reveals two distinct energy…

Superconductivity · Physics 2009-11-07 H. Schmidt , J. F. Zasadzinski , K. E. Gray , D. G. Hinks

The progress in investigation of two-band superconductor MgB$_2$ by the point-contact spectroscopy (PCS) is given. Results of study of superconducting gap temperature and magnetic field dependence for two-dimensional $\sigma$ and…

Superconductivity · Physics 2007-05-23 I. K. Yanson , Yu. G. Naidyuk

We report scanning tunneling spectroscopy (STS) measurements of the gap properties of both ceramic MgB2 and c-axis oriented epitaxial MgB2 thin films. Both show a temperature dependent zero bias conductance peak and evidence for two…

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