Related papers: Carbon substitution effect in MgB$_2$
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…
We study the effects of pressure on the electron-phonon interaction in MgB_2 using density-functional-based methods. Our results show that the superconductivity in MgB_2 vanishes by 100 GPa, and then reappears at higher pressures. In…
We report that the ternary MgB2-xCx compounds adopt an isostructural AlB2-type hexagonal structure in a relatively small range of nominal carbon concentration, x<0.1. The lattice parameter a decreases almost linearly with increasing carbon…
We report data on the thermal conductivity \kappa(T,H) in the basal plane of hexagonal single-crystalline and superconducting Mg(B_{1-x}C_x)_2 (x= 0.03, 0.06) at temperatures between 0.5 and 50 K, and in external magnetic fields H between 0…
The recent discovery of superconductivity at ~39 K in MgB2, by Nagamatsu et al. establishes this simple binary compound as having the highest bulk superconducting transition temperature, Tc, of any non-copper-oxide material. Much of the…
Effects of magnetic impurity on the superconductivity has been investigated in Mg1-xMnB2. With increase of Mn concentration x, the lattice constant c (perpendicular to the boron sheet) decreases at a rate of -1.4 % (= dlnc/dx), while a…
We prepared MgB$_{2-x}$Be$_{x}$ ($x=0$, 0.2, 0.3, 0.4, and 0.6) samples where B is substituted with Be. MgB$_{2}$ structure is maintained up to $x=0.6$. In-plane and inter-plane lattice constants were found to decrease and increase,…
Growth of carbon substituted magnesium diboride Mg(B1-xCx)2 single crystals with 0<x<0.15 is reported and the structural, transport, and magnetization data are presented. The superconducting transition temperature decreases monotonically…
Measurements of the superconducting upper critical field, H_{c2}, and critical current density, J_c, have been carried out for MgB_2 doped with Ti and/or C in order to explore the problems encountered if these dopants are used to enhance…
We present details of synthesis optimization and physical properties of nearly single phase carbon doped MgB2 with a nominal stoichiometry of Mg(B{0.8}C{0.2})2 synthesized from magnesium and boron carbide (B4C) as starting materials. The…
The Andreev reflection measurements of the superconducting energy gap in the carbon-substituted MgB$_2$ are presented. Despite the strong suppression of the transition temperature by 17 K in comparison with the pure MgB$_2$, the same…
We have studied the changes in the electronic structure and the superconducting transition temperature T_c of Mg(B_{1-x}C_{x})_{2} alloys as a function of x with 0\leq x\leq 0.3. Our density-functional-based approach uses coherent-potential…
We report indications of a phase transition in carbonaceous MgB2 above 9 GPa at 300 K after stress relaxation by laser heating. The transition was detected using Raman spectroscopy and X-ray diffraction. The observed changes are consistent…
The superconducting and structural properties of a series of Mg1-xAlxB2 samples have been investigated. X-ray diffraction results confirmed the existence of a structural transition associated with the significant change in inter-boron layer…
The basic magnetic and electronic properties of most binary compounds have been well known for decades. Therefore the recent announcement of superconductivity at 39 K in the simple binary ceramic compound MgB2 is surprising. This compound,…
The hydrostatic pressure effect on the newly discovered superconductor MgB2 has been determined. The transition temperature Tc was found to decrease linearly at a large rate of -1.6 K/GPa, in good quantitative agreement with the ensuing…
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…
Solid MgB$_2$ has rather interesting and technologically important properties, such as a very high superconducting transition temperature. Focusing on this compound, we report the first non-trivial application of a novel…
Hydrogenation of MgB_2 powder has lead to an increase in the superconducting temperature, as determined by ac susceptibility. Applied dc fields reduce the transition temperature in the same ratio as for the pure powder.
In this paper, we reported the structural properties and superconductivity of Mg(B1-xCx)2 compounds. Powder x-ray diffraction results indicate that the samples crystallize in a hexagonal AlB2-type structure. Due to the chemical activity of…