Carbon doping of superconducting magnesium diboride

Abstract

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 superconducting transition temperature is ~ 22 K (~ 17 K lower than in pure MgB2). The temperature dependence of the upper critical field is steeper than in pure MgB2 with Hc2(10K) ~ 9 T. Temperature dependent specific heat data taken in different applied magnetic fields suggest that the two-gap nature of superconductivity is still preserved for carbon doped MgB2 even with such a heavily suppressed transition temperature. In addition, the anisotropy ratio of the upper critical field for T/Tc ~ 2/3 is gamma ~ 2. This value is distinct from 1 (isotropic) and also distinct from 6 (the value found for pure MgB2).

11 pages, 13 figures, submitted to Physica C

References in corpus (18)

• Beyond Eliashberg superconductivity in MgB2: anharmonicity, two-phonon scattering, and multiple gaps
• Boron Isotope Effect in Superconducting MgB${}_2$
• Superconductivity in Dense $Mg{B}_2$ Wires
• Specific Heat of Mg ^{11}B_2
• Thermodynamic and Transport Properties of Superconducting $M{g}^{10}{B}_2$
• First-Principles Calculation of the Superconducting Transition in MgB2 within the Anisotropic Eliashberg Formalism
• Specific heat in the superconducting and normal state (2-300 K, 0-16 Teslas), and magnetic susceptibility of the 38-K superconductor MgB2: evidence for a multicomponent gap
• Intralayer Carbon Substitution in the MgB2 Superconductor
• Electronic structure of superconducting MgB2 and related binary and ternary borides
• Order parameter of MgB_2: a fully gapped superconductor
• Magnetoresistivity and Complete $H_{c2}(T)$ in $Mg{B}_2$
• Carbon solubility and superconductivity in MgB2
• Determination of superconducting anisotropy from magnetization data on random powders as applied to LuNi${}_2$B${}_2$C, YNi${}_2$B${}_2$C and MgB${}_2$
• Effect of Carbon-Doping in Bulk Superconducting MgB2 Samples
• Thermoelectric power and transport properties of pure and Al-doped MgB2
• Temperature-dependent $H_{c2}$ anisotropy in MgB${}_2$ as inferred from measurements on polycrystals
• Effects of stoichiometry, purity, etching and distilling on resistance of MgB2 pellets and wire segments
• The complex superstructure in Mg1-xAlxB2 at x~0.5

Cited by in corpus (51)

• Systematic effects of carbon doping on the superconducting properties of Mg(B${}_{1-x}$C${}_x$)${}_2$
• Carbon substitution in MgB2 single crystals: structural and superconducting properties
• Probing multiband superconductivity by point-contact spectroscopy
• Carbon-substituted MgB2 single crystals
• Crystal Chemistry of Carbon-Substituted MgB2
• Band filling and interband scattering effects in MgB${}_2$: C vs Al doping
• Significantly enhanced critical current densities in MgB2 tapes made by a scaleable, nano-carbon addition route
• Carbon-substitution effect on the electronic properties of MgB${}_2$ single crystals
• Prospects for Improving the Intrinsic and Extrinsic Properties of Magnesium Diboride Superconducting Strands
• Large Upper Critical Field and Irreversibility Field in MgB2 wires with SiC additions
• Nanoscale-SiC doping for enhancing Jc and Hc2 in the Superconducting MgB2
• Observation of the Crossover from Two-Gap to Single-Gap Superconductivity through Specific Heat Measurements in Neutron Irradiated MgB2
• Improved critical current densities in B4C doped MgB2 based wires
• The different development of the anisotropic upper critical field in MgB2 by aluminum and carbon doping
• Thermodynamics of Two - Band Superconductors: The Case of MgB${}_2$
• Effects of Boron Purity, Mg Stoichiometry and Carbon Substitution on Properties of Polycrystalline MgB${}_2$
• The doping effect of multiwall carbon nanotube on MgB2/Fe superconductor wire
• Enhancement of the irreversibility field by carbon substitution in single crystal MgB${}_2$
• Evidence for Single-gap Superconductivity in Mg(B_{1-x}C_x)_2 Single Crystals with x=0.132 from Point-Contact Spectroscopy
• Carbon-substitution dependent multiple superconducting gap of MgB${}_2$: a "sub-meV" resolution photoemission study
• Systematic study of the two band/two gap superconductivity in carbon-substituted MgB2 by point-contact spectroscopy
• Retention of Two-Band Superconductivity in Highly Carbon-Doped MgB2
• Electrons and phonons in the ternary alloy CaAl${}_{2-x}$Si${}_x$} as a function of composition
• Two band/two gap superconductivity in carbon-substituted MgB2 evidenced by point-contact spectroscopy
• Enhancement of Critical Current Density in low level Al-doped MgB2
• Influence of the upper critical field anisotropy on the transport properties of polycrystalline MgB${}_2$
• Point-contact spectroscopy of Al- and C-doped MgB2. Superconducting energy gaps and scattering studies
• Influence of Al doping on the critical fields and gap values in magnesium diboride single crystals
• Influence of carbon substitution on the heat transport in single crystalline MgB2
• Increases in the Irreversibility Field and the Upper Critical Field of Bulk MgB2 by ZrB2 Addition
• Superconducting Properties of adipic acid doped Bulk MgB2 Superconductor
• High-energy ball milling and synthesi temperature study to improve superconducting properties of MgB2 ex-situ tapes and wires
• Comment on: "Band Filling and Interband Scattering Effects in MgB2: Carbon versus Aluminium Doping"
• Role of charge doping and lattice distortions in codoped Mg_{1-x}(AlLi)_{x}B_2 compounds
• Superconductivity in MgB_2 doped with Ti and C
• Electron scattering dependence of dendritic magnetic instability in superconducting MgB2 films
• Electron-phonon coupling and two-band superconductivity of Al- and C-doped MgB2
• Infrared properties of Mg${}_{1-x}$Al${}_x($B${}_{1-y}$C${}_y$)${}_2$ single crystals in the normal and superconducting state
• Synthesis of Mg(B${}_{1-x}$C${}_x$)${}_2$ Powders
• Role of Carbon in Enhancing the Performance of MgB2 superconductor
• Local Tunneling Study of Three-Dimensional Order Parameter in the $\pi$-band of Al-doped MgB${}_2$ Single Crystals
• Effect of PVA doping on flux pinning in Bulk MgB2
• Effect of pressure on the superconducting transition temperature of doped and neutron-damaged MgB2
• Theory of vortices in hybridized ballistic/diffusive-band superconductors
• The effect of {11}^B substitution on the superconductivity in MgCNi3
• Raman Scattering Investigation of Electron Phonon Coupling in Carbon substituted MgB2
• Effects of Neutron Irradiation on Carbon Doped MgB2 Wire Segments
• ${}^{11}$B NMR study of pure and lightly carbon doped MgB${}_2$ superconductors
• Is Delta_{pi}-gap-only superconductivity possible in Mg_{1-x}Al_{x}B_{2} and Mg(B_{1-y}C_{y})_{2} alloys?
• Effect of doping on irreversible Campbell length in MgB${}_2$ single crystals
• Enhancing long-range order in disordered two-band s-wave superconductors