On the calculation of Tc's of superconducting binary alloys based on two-phonon exchange mechanism

By making use of the available experimental heat capacity data and a recently proposed equation based on the multiple phonon-exchange mechanism, we present here the results of ab-initio calculation of Tc's of some of the binary superconducting alloys in the following scenarios: (a) the alloy is characterized by a single Debye temperature and (b) the alloy is characterized by two Debye temperatures. The latter scenario follows from the suggestion that phonons corresponding to the two sub-lattices in the alloy simulate, in a first approximation, the modes of vibration of two weakly coupled harmonic oscillators