  We study theoretically the electronic entropy and specific heat in diffusive
superconductor-normal metal-superconductor (SNS) Josephson junctions. In
particular, we consider the influence of non-idealities occurring in an actual
experiment, such as the presence of barriers at the NS interfaces, the
spin-flip and inelastic scattering in the N region and quasiparticle subgap
states in the superconductors. We find that spin-flip and inelastic scattering
do not have, for typical parameters values, a large effect. On the contrary,
the presence of barriers suppresses the superconducting correlations in the N
region, with the consequence that the entropy and the specific heat get reduced
eventually to those in the absence of superconductivity for opaque interfaces.
Finally we suggest an experiment and check that it is possible, under realistic
conditions, to measure the dependence of electronic specific heat on the phase
difference between the superconductors.
