Inelastic electron scattering influence on the strong coupling oxide superconductors

The superconducting order parameters Δ and energy gap Δg are calculated taking into account the pair-breaking inelastic quasiparticle scattering by thermal Bose-excitations, e.g., phonons. The treatment is self-consistent because the scattering amplitude depends on Δ. The superconducting transition for any strength of the inelastic scattering is the phase transition of the first kind and the dependences Δ (T) and Δg (T) tend to rectangular curve that agrees well with the experiment for high-Tc oxides. On the basis of the developed theory the nuclear spin-lattice relaxation rate Rs in the superconducting state is calculated. The Hebel-Slichter peak in Rs(T) is shown to disappear for strong enough inelastic scattering