Superconductivity and the Fermi surface of Tc

Abstract

Results of bandstructure calculations of Tc, which has a HCP lattice structure, are used to calculate the superconducting transition temperature T_c and the Fermi surface of the metal. The strong-scattering theory of Gaspari and Gyorffy (1972) is used in conjunction with McMillan's formula (1968) to calculate T_c in the spherical band approximation. As the bandstructure calculations were made for potentials constructed with and without correlation, the superconducting transition temperature is calculated for all potentials. The theoretical values of T_c are found to be very sensitive to changes in the electron-phonon enhancement factor lambda and the Coulomb pseudopotential mu *. However the theoretical value of T_c calculated for a potential which includes correlation agrees well with the experimental value for a particular choice of mu *. The Fermi surface cross sections are obtained for all the potentials and a qualitative comparison is made with the available preliminary experimental results.