2 research outputs found
Superconductivity in two-band systems with variable charge carrier density. The case of MgB2
The theory of thermodynamic properties of two-band superconductor with
reduced density charge carriers is developed on the base of phonon
superconducting mechanism with strong electron-phonon interaction. This theory
is adapted to describe the behavior of critical temperature Tc, energy gaps
Delta1, Delta2, and the relative jump of electron specific heat (Cs - Cn)/Cn in
the point T = Tc along with the variation of charge carrier density in the
compound MgB2 when substitutional impurities with different valence are
introduced into the system. It is shown, that according to the filling
mechanism of energy bands which overlap on Fermi surface, the quantities Tc,
Delta1, Delta2 decrease when this compound is doped with electrons and remain
constant or weakly change when the system is doped with holes. The theory
qualitatively agrees with the experimental data. Also is shown that the
consideration of inter- and intraband scattering of electrons on impurity
potential improves this agreement.Comment: 19 pages, 6 figures, 1 table. to be published in JETP (first number
2007