English
Related papers

Related papers: Carbon substitution effect in MgB$_2$

200 papers

The effect of pressure on optical phonon frequencies of MgB$_2$ has been calculated using the frozen-phonon approach based on a pseudopotential method. Gr\"uneisen parameters of the harmonic mode frequencies are reported for the…

Superconductivity · Physics 2009-11-07 K. Kunc , I. Loa , K. Syassen , R. K. Kremer , K. Ahn

We report a detailed study of the electronic structure of the MgB$_{2}$ with different lattice constants by using the full-potential linearized augmented plane wave(FPLAPW) method. It is found that the lattice parameters have great effect…

Materials Science · Physics 2009-11-07 Xiangang Wan , Jinming Dong , Hongming Weng , D. Y. Xing

The critical temperature (TC) of MgB2, one of the key factors limiting its application, is highly desired to be improved. On the basis of the meta-material structure, we prepared a smart meta-superconductor structure consisting of MgB2…

Superconductivity · Physics 2017-12-04 Honggang Chen , Yongbo Li , Guowei Chen , Longxuan Xu , Xiaopeng Zhao

Cryogenic scanning tunneling microscopy and magnetization measurements were used to study the superconducting properties of MgB_2. The magnetization measurements show a sharp superconductor transition onset at T_c = 38.5 K, in agreement…

Superconductivity · Physics 2009-11-07 Amos Sharoni , Israel Felner , Oded Millo

The MgB$_2$ superconductor, discovered in 2001, has provided unique compound features of magnesium diboride with much higher critical temperature and critical field compared to NbTi superconductor. Its applications have been expanding owing…

Accelerator Physics · Physics 2022-02-18 Akira Yamamoto

High-density bulk materials of a newly discovered 40K intermetallic MgB2 superconductor were prepared by high pressure sintering. Superconducting transition with the onset temperature of 39K was confirmed by both magnetic and resistive…

Superconductivity · Physics 2009-11-07 Y. Takano , H. Takeya , H. Fujii , H. Kumakura , T. Hatano , K. Togano , H. Kito , H. Ihara

Superconducting MgB2 was synthesized in a stainless steel tube which compressed by pulsed magnetic field. The temperature dependence of diamagnetic moment m(T) was investigated and the pinning potential was determined

Superconductivity · Physics 2007-05-23 S. P. Ananev , V. A. Grinenko , V. A. Keilin , E. P. Krasnoperov , P. A. Levit , V. A. Stoliarov

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

Thin films of MgB2 superconductor were prepared by three different procedures on sapphire and silicon substrates. Boron thin films, ex-situ annealed in magnesium vapour, resulted in textured polycrystalline films with crystal dimensions…

Superconductivity · Physics 2009-11-07 A. Plecenik , L. Satrapinsky , P. Kus , S. Gazi , S. Benacka , I. Vavra , I. Kostic

The size effect of the raw B powder on the MgB2 phase formation has been studied by the technique of in-situ high temperature resistivity (HT-rT) measurement. The onset temperature, Tonset, and the completion temperature, TPF, of the phase…

Superconductivity · Physics 2007-05-23 Ling An , Chinping Chen , Bo Wang , Cheng-gang Zhuang , Xing-guo Li , Zeng-jun Zhou , Qing-rong Feng

The thermal expansion coefficient $\alpha$ of MgB$_2$ is revealed to change from positive to negative on cooling through the superconducting transition temperature $T_c$. The Gr\"uneisen function also becomes negative at $T_c$ followed by a…

Superconductivity · Physics 2009-11-11 J. J. Neumeier , T. Tomita , M. Debessai , J. S. Schilling , P. W. Barnes , D. G. Hinks , J. D. Jorgensen

We have studied the evolution of superconducting and normal state properties of neutron irradiated Mg(B$_{.962}$C$_{.038}$)$_2$ wire segments as a function of post exposure annealing time and temperature. The initial fluence fully…

The small atomic mass of boron indicates strong electron-phonon coupling, so it may have a brilliant performance in superconductivity. Recently, a new 2D boride sheet with ordered metal vacancies and surface terminals (Mo4/3B2-x) was…

Superconductivity · Physics 2023-11-14 Xiaoran Shi , Junfeng Gao , Shi Qiu , Yuan Chang , Luneng Zhao , Zhen-Guo Fu , Jijun Zhao , Ping Zhang

The specific heat of two polycrystalline samples of MgB_2 is presented and analyzed (2 - 300 K, 0 - 16 T), together with magnetic properties. The main characteristics are a low density of states at the Fermi level, high phonon frequencies,…

Superconductivity · Physics 2007-05-23 Alain Junod , Yuxing Wang , Frederic Bouquet , Pierre Toulemonde

The boride compounds MB_x related to the magnesium-boron stacking layered material MgB2 are discussed in terms of the B-B layers in the borides analogous to the Cu-O ones in the cuprates. We propose a possibility of superconducting…

Superconductivity · Physics 2009-11-07 Chikao Kawabata , Nobuhiko Hayashi , Fumihisa Ono

An anisotropic lattice anomaly near the superconducting transition temperature, Tc, was observed in MgB2 by high-resolution neutron powder diffraction. The a-axis thermal expansion becomes negative near Tc, while the c-axis thermal…

Superconductivity · Physics 2007-05-23 J. D. Jorgensen , D. G. Hinks , P. G. Radaelli , W. I. F. David , R. M. Ibberson

Bulk samples of MgB2 have been formed by hot isostatic pressing (HIPping) of commercial powder at 100MPa and 950=B0C. The resulting material is 100% dense with a sharp superconducting transition at 37.5K. Microstructural studies have…

Superconductivity · Physics 2009-11-07 T C Shields , K Kawano , D Holdom , J S Abell

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…

Structural, magnetic and magnetocaloric properties of Mn2-xCrxSb compounds have been studied. In these compounds a first order magnetic phase transition from the ferrimagnetic to the antiferromagnetic state occurs with decreasing…

Materials Science · Physics 2014-10-01 L. Caron , X. F. Miao , J. C. P Klaasse , S. Gama , E. Brück

We have investigated the temperature and magnetic field dependence of the Hall coefficient of two well-characterized superconducting MgB$_2$ films (T$_{c0}$=38.0 K) in both the normal and superconducting states. Our results show that the…

Superconductivity · Physics 2007-05-23 R. Jin , M. Paranthaman , H. Y. Zhai , H. M. Christen , D. K. Christen , D. Mandrus