2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/24231The exact formula of Tc's equation and the isotope effect exponent of two-band s-wave superconductors in weak-coupling limit are derived by considering the influence of interband interaction. The paring interaction in each band consisted of 2 parts : the electron-phonon interaction and non-phonon interaction are included in our model. The isotope effect exponent of MgB2 equal to 0.3 with Tc 40 K can be found in the weak coupling regime and interband interaction of electron-phonon interaction show more effect on isotope effect exponent than of non-phonon interaction.10 pages, 2 figures. submit to Physica Status Solidi (b)Superconductivitytext