THERMODYNAMIC PROPERTIES OF 2-BAND SUPERCONDUCTORS WITH NONPHONON SUPERCONDUCTIVITY MECHANISM

The dependence of the superconductivity transition temperature T(c), the energy pp at T = 0 K and the electron specific heat jump at T = T(c) on the carrier concentration (x) is considered on the basis of a two-band model with a non-phonon superconductivity mechanism. This model takes into account both intraband interactions and interband ones without any restrictions on their character. The possibility to acquire a high T(c) is shown both for the case of attraction and for the case of repulsion of carriers. A small value of the relative electron specific heat jump ((C(S)-C(N))/C(N) < 1.43) and also a maximum in the absolute one in dependence on x at that value of x which corresponds to maximum T, is found. It is shown that values of the ratio 2\DELTA(n)(O)\/T(c) can be substantially different from 3.54.