Related papers: Anisotropic s-wave superconductivity in MgB_2
The influence of anisotropy on the transport current in MgB$_2$ polycrystalline bulk samples and wires is discussed. A model for the critical current density is proposed, which is based on anisotropic London theory, grain boundary pinning…
Electronic heat capacity was calculated for a mesoscopically disordered s-wave superconductor treated as a spatial ensemble of domains with a continuously varying superconducting properties. The domains are assumed to have sizes larger than…
The temperature dependence of the London penetration depth ($\lambda$) and coherence length ($\xi$) has been deduced from Hall probe magnetization measurements in high quality MgB$_2$ single crystals in the two main crystallographic…
Superconducting properties of hypothetical simple hexagonal CaB2 are studied using the fully anisotropic Eliashberg formalism based on electronic and phononic structures and electron-phonon interactions which are obtained from ab initio…
The complex conductivity of a MgB2 film has been investigated in the frequency range 4 cm^{-1}< nu < 30 cm^{-1} and for temperatures 2.7 K < T <300 K. The overall temperature dependence of both components of the complex conductivity is…
In this work we review our present understanding of superconductivity in Magnesium Diboride from the theoretical perspective as it evolves from band structure calculations. Particular emphasis is placed on two gap superconductivity. Some of…
The recently discovered intermetallic superconductor MgB2 appears to have a highly anisotopic upper critical field with Hc2(max)/Hc2(min} = \gamma > 5. In order to determine the temperature dependence of both Hc2(max) and Hc2(min) we…
In this paper we present the resistivity, the Seebeck effect, and the thermal conductivity measurements on a MgB2 sintered sample. Such transport properties highlight the role of the junctions between the grains to a different extent. In…
A large number of experimental facts and theoretical arguments favor a two-gap model for superconductivity in MgB$_{2}$. However, this model predicts strong suppression of the critical temperature by interband impurity scattering and,…
Field and temperature microwave measurements have been carried out on MgB2 thin film grown on Al2O3 substrate. The analysis reveals the mean field coherence length xi_{MF} in the mixed state and a temperature independent anisotropy ratio…
The optical conductivity measurements give a powerful tool to investigate the nature of the superconducting gap for conventional and unconventional superconductors. In this article, first, general analyses of the optical conductivity are…
The upper critical fields, $H_{c2}$($T$), of single crystals of the superconductor Ca$_{10}$(Pt$_{4-\delta}$As$_{8}$)((Fe$_{0.97}$Pt$_{0.03}$)$_{2}$As$_{2}$)$_{5}$ ($\delta$ $\approx$ 0.246) are determined over a wide range of temperatures…
Far-infrared reflectance of a MgB2 film has been measured by Fourier-transform spectroscopy for frequencies 10 cm^{-1}<\nu <4000 cm^{-1} above and below the superconducting transition. The data provide clear experimental evidence for the…
We present data on temperature-dependent anisotropy of the upper critical field of MgB$_2$ obtained from the analysis of measurements on high purity, low resistivity polycrystals. The anisotropy decreases in a monotonic fashion with…
The two-gap model for superconductivity in MgB2 predicts that interband impurity scattering should be pair breaking, reducing the critical temperature. This is perhaps the only prediction of the model that has not been confirmed…
The anisotropy of MgB2 is still under debate: its value, strongly dependent on the sample and on the measuring method, ranges between 1.2 and 13. In this work we present our results on a MgB2 c-oriented superconducting thin film. To…
We report the preparation method of, and boron isotope effect for MgB$_2$, a new binary intermetallic superconductor with a remarkably high superconducting transition temperature $T_c$($^{10}$B) = 40.2 K. Measurements of both temperature…
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…
OsB_2 crystallizes in an orthorhombic structure (Pmmn) which contains alternate boron and osmium layers stacked along the c-axis. The boron layers consist of puckered hexagons as opposed to the flat graphite-like boron layers in MgB_2.…
It is well established that the superconductivity in the recently discovered superconducting compound MgB$_{2}$ resides in the quasi-two-dimensional band ($\sigma$-band) and three-dimensional band ($\pi$-band). We demonstrate that, due to…