Influence of the electron-electron coupling parameters on the temperature of the superconducting transition in compounds with the A-15 structure

The electronic structure of the A-15 compounds is investigated with allowan ce for the Hubbard energy as the largest energy parameter. The conditions f or the onset of Cooper instability are obtained. The dependence of the supe rconducting transition temperature on the degree of filling of the d and p shells of the transition elements and nontransition elements is determined. The relation between the transition temperature and the energy of a hop al ong the chains is established, permitting a comparison with experiment. A q ualitative explanation is given for the empirical results of Matthias. (C) 2000 MAIK "Nauka/ Interperiodica".