Calculation and measurement of the electronic part of the thermal conductivity of a strong-coupling superconductor in which elastic scattering of the electrons dominates

We have generalized the theoretical expression for the electronic contribution $K_{es}$ to the thermal conductivity in strong-coupling superconductors to include elastic scattering of the electrons. In the limit where the elastic scattering dominates, the resulting expression for $K_{es}$ is equivalent to that of Bardeen, Rickayzen, and Tewordt except for a change in the energy-gap width; the renormalization function Z_s does not explicitly appear. We have made measurements of the thermal conductivity of quench-condensed lead films which are in very good agreement with the theory, with no adjustable parameters.