Theory for Superconductivity in d-Band Metals

Abstract

Superconductivity in transition metals, in transition metal alloys, in A‐15 compounds and in ${\mathrm{U}}_6\mathrm{X}$ compounds is studied within the framework of the B.C.S. theory. The electron‐phonon coupling constant λ is expressed in terms of measureable normal‐state quantities and an atomic parameter. Then, using the McMillan formula for the superconducting transition temperature T_c, the variation of T_c in the three transition metal series is discussed. Calculated values for T_c are given for several transition metal alloys, ${\mathrm{U}}_6\mathrm{X}$ compounds and for Sc, Y, Lu, and La. Also, it is shown that in A15 compounds Cooper pair fluctuations may occur even at temperatures several degrees Kelvin above T_c.