New approach to the thermal Casimir force between real metals
  The new approach to the theoretical description of the thermal Casimir force between real metals is presented. It uses the plasma-like dielectric permittivity that takes into account the interband transitions of core electrons. This permittivity precisely satisfies the Kramers-Kronig relations. The respective Casimir entropy is positive and vanishes at zero temperature in accordance with the Nernst heat theorem. The physical reasons why the Drude dielectric function, when substituted in the Lifshitz formula, is inconsistent with electrodynamics are elucidated. The proposed approach is the single one consistent with all measurements of the Casimir force performed up to date. The application of this approach to metal-type semiconductors is considered. 
V. M. Mostepanenko and B. Geyer