The Pseudopotential Dependence of Superconducting Properties in Carbon Doped MgB2

摘要

The Pseudopotential theory in BCS-Eliasberg-McMillan model has been extended for the Carbon doped MgB2 superconductor for the theoretical investigation of superconductivity in MgB2-xCx system. The Superconducting state parameters viz. Electron-phonon coupling strength (λ), Coulomb pseudopotential (μ*), Transition-temperature (T_c), Isotope effect exponent (a) and Effective interaction strength (NoV) have been obtained for MgB2-xC_x alloys (where 0.00 < x < 0.20) for different concentration. The superconducting state parameters are calculated by using three forms of pseudopotential viz. Ashcroft's, Linear and Gajjar potential in conjunction with RPA form of dielectric screening due to Gellmann and Brueckner. The Rowell's T_c equation predicted for MgB2-xC_x, does not work well for this whereas the present formulation almost reproduces the experimental T_c value for MgB2-xC_x superconductor.